Rubber Gloves
Soap Carvings
Aircraft Cabinets
Motorcycle Brake Locks

It was an american nurse's sensitivity to an antiseptic that led to the development of medical rubber gloves.

The year was 1890, and the hospital was johns hopkins in baltimore.

Sympathetic to the nurse's plight, the chief of surgery asked a rubber company to develop protective gloves.

Around the world, healing hands wear rubber gloves to stop the spread of germs and save lives.

To make them, they need a lot of hands, the kind made from ceramic or aluminum.

They'll serve as molds.

First, they need to remove residue from the last rubber-glove production, so they do a thorough washing in soapy water...

And then in bleach.

They must remove every speck of residue because even the smallest contaminate could lodge in the latex rubber gloves and create holes.

Leaving the bleach, the ceramic hands twirl into round, revolving brushes.

Their bristles scour the surface and the hard to reach areas between the ceramic fingers.

After this thorough scrubbing, the hand molds dive into a tub of hot water.

It's the last cleaning before production begins.

As they exit the tub, the hands swivel on the rail carrier to drip dry.

Still slightly damp and spinning, the hand molds head into a chemical bath, which forms a film on the surface.

It's a critical coating because liquid rubber won't adhere to bare ceramic, but it will to this substance.

The ceramic molds now reach into warm, liquid rubber, which has been enhanced for extra strength.

The liquid rubber reacts with the chemical coating on the hands and becomes gel-like.

Coated with the rubber gel, the hands spin to shake off any drops as they head into an oven.

Under intense heat, the rubber dries to the hand form.

It also undergoes a chemical process called vulcanization that makes rubber stronger and elastic.

After a wash and dry, the gloves spin through brushes which roll up the cuffs.

This cuff roll, called the bead, has a specific purpose.

It makes it easier to pull the rubber glove off the mold.

Workers grab the gloves by the beads to peel them off the ceramic forms.

These particular medical gloves were molded from synthetic rubber for people who can't wear natural latex rubber due to allergies.

These synthetic rubber gloves are a bit stickier than the natural latex ones, and they must be removed by hand.

However, the natural latex gloves come off much more easily.

Bursts of pressurized air blow these gloves off the ceramic forms.

At a test station, a worker now stretches and inflates each medical glove to check for weak spots and holes.

Even a pinhole leak would be cause for rejection.

Next, they take a sample glove from every batch and pump water into it, again checking for leaks.

If the sample glove is watertight, they approve the entire batch for shipment.

They color code gloves for strength.

These orange cleaning gloves are thick and reusable.

Others, like the medical gloves, are for limited use and disposable.

Each rubber formulation is customized for color, strength, and other characteristics.

It has taken a lot of fake hands and real ones to make rubber gloves, and it all happens very fast.

They manufacture 200 rubber gloves a minute at this factory.

That's about 12,000 gloves per hour.

They pack them up in batches of 100.

A cornstarch solution applied earlier keeps them from sticking together in the box.

Later, that starch will also act as a lubricant to allow the gloves to slide easily onto hands.

And with all that, these rubber gloves are ready to protect the public.

In northern thailand, the tradition of carving elaborate flowers from soap began in the 1930s with farm workers who were looking for a creative outlet.

In their hands, pieces of soap became little works of art.

And in the process, they carved out a niche market for soap flowers.

Today in thailand, there's a thriving tourist trade in floral soap carvings.

These awesome blossoms are far too delicate for scrub-up duty.

They're made to be admired.

Infused with fruit powders, they also add fragrance to a room.

The carvers start by making their own soap.

Glycerin made of animal fats and oils is the main ingredient.

Other ingredients include fruit powder...

Water...

Food coloring--  in this case, yellow-- fragrance...

And vegetable oil.

He mixes the vegetable oils with the water as he heats the ingredients slowly.

He then adds the glycerin chunks to a separate bucket of hot water.

The glycerin melts on contact, and he whisks it to disperse it in the water.

He now pours the glycerin mixture in to the water and oil.

Using an electric mixer, he blends the ingredients, adding water as needed to achieve the desired consistency.

He blends the mango fruit powder into the soap mixture.

A dash of yellow coloring reflects the aroma of the soap-- mango.

He adds a mango fragrance formulation to enhance the powdered fruit scent.

That completes this aromatic liquid-soap mixture.

He transfers it to a square pan lined with plastic.

After a few hours, the soap solidifies into a big yellow bar.

He pries the hardened soap and the plastic liner away from the pan and flips it over.

The soap slab lands on the workbench.

He peels the plastic liner off.

Now, using a device similar to a paper cutter, he slices the soap into long, uniform bars.

He stacks them in piles of three.

He cuts the stacks of long bars crosswise, producing small soap squares the size of brownies.

Each soap bar will be transformed into a beautiful flower.

This takes artistic vision and skill.

The artist has many years of experience and carves with an expert hand.

As he scoops out chunks, the broad and distinctive petals of an orchid take shape.

He discards the broad base, and from a simple soap bar, a flower has bloomed.

He dips the carving in water to improve the adhesion of water-based paint.

He partially submerges the carving in paint, giving it a two-toned look.

The artist selects color combinations for their visual impact, and authenticity is not essential.

He brushes mauve paint onto the orchid's central column to accentuate it.

He extends the brush strokes to the petals.

These brush strokes mimic the look of veins.

With this colorful artistry, the soap carving seems to come to life.

He dips a toothbrush in paint and flicks his thumb across the bristles to spray flecks onto the center column.

With that final splash of color, the carving is complete.

He glues it to the base of a decorative box.

The box both protects the carving and adds to the presentation.

Taking the lid off reveals a surprise.

The carving could be any flower in any color.

But the most amazing thing of all is that it's been carved from soap.

The world of private-passenger aircraft is all about comfort and luxury.

Big corporations send their top executives to travel in jets with well-appointed interiors.

And the world's super-wealthy spare no expense making their private planes as lavish as their homes.

Just like building or renovating a house, you can choose all the decorative finishings of your new aircraft-- everything from the floor covering and seat fabric to the style, wood type, and color of the cabinetry.

It's critical not to weigh the aircraft down, so cabinets can't be made from particle board.

Even plywood is far too heavy.

The solution-- panels made of honeycomb-shaped hard paper sandwiched between fiberglass sheets, strong like particle board, but 1/4 the weight.

Computerized machines cut the panels to shape and drill holes for threaded inserts, into which bolts and screws for hinges and handles will fasten.

After refining the holes with hand tools, workers hold the inserts in the holes with tape while they inject epoxy glue to bond the inserts permanently.

The panels adjoin with a tongue and groove system, so computerized machines cut the edges accordingly.

The material is fibrous, so the cut edges are rough.

Workers smooth them before gluing and assembling.

Certain panel surfaces are too hard to access after assembly, so they receive their decorative wood veneer facade before being cut to shape.

These pieces are covered in a protective film to prevent damaging the veneer during assembly.

Once a unit is assembled, workers make sure it's square.

They also verify the dimensions.

Meanwhile, an automated belt sander preps the veneer.

Veneer is wood that's been sliced into thin sheets.

For these cabinet facades, these sheets are a mere 0.04 inches thick.

The most typical choices are walnut, ebony, cherry, and birch.

Workers disassemble the unit to access each component for veneering.

They lay the component on the back of the veneer sheet and trace it.

Then they follow the pencil line with a fine-tooth veneer saw.

Next, they spray contact cement on the component surface and the veneer's underside.

A plastic sheet in between prevents contact until the veneer is correctly positioned.

After pressing down the veneer, they place the component in a vacuum bag and suction out the air.

This flattens the veneer evenly over the entire surface.

Eight hours later, the component comes out of the vacuum bag, and with a router, they trim the veneer flush all around.

Then they glue the edges with epoxy and apply strips of hardwood to match the facade.

The epoxy cures in a couple of hours, at which point they sand the edges to remove any excess glue.

Now they reinstall the component and measure to make sure the surrounding gaps are precisely 0.06 inches.

Should some tweaking be required, they simply sand edges or adjust hinges.

They disassemble yet again and touch up any imperfections that sanding the edges caused.

Once the touch-up paint is dry, they spray on the first of nine coats of lacquer.

Each coat has to dry overnight.

They sand it twice before applying the next coat, first with an orbital sander, then with a sanding block to remove any waves in the lacquer left by the orbital sander.

After the last coat of lacquer dries, they do a final sanding with a very fine grit paper.

Then, using a wool pad and polishing compound, they polish the surface to a reflective, high-gloss finish.

Workers now reassemble the components for the last time.

They install the fixtures and accessories, the decorative hardware, and everything electrical.

The cabinetry unit is finished.

Not only does the luxurious look fit a multi-million-dollar private aircraft, it's also, as they say in tech terms, plug and play.

You just install and plug it into the aircraft, and everything runs--  no additional wiring required.

A motorcycle can be rolled into a truck or van and be gone in a minute, leaving an empty space and an angry owner.

To help put the brakes on this parking-lot theft, there are portable locks for brakes.

With the brakes in full lock down, the bike can't be rolled away.

When it's time for a pit stop, a disc-brake lock takes some of the worry out of leaving a coveted motorbike unguarded.

Simply clip it onto the motorbike's brake rotor, turn the key, and the wheels won't budge.

Equipped with an alarm, this handy gadget can also alert bystanders of a crime in progress.

Before they manufacture the lock, they cut the keys.

There are two for each lock.

The employee inserts two blank key blades into milling machines that carve eight different notches into them.

The combination of notches is one of over a million possible key codes.

The machine prints the key-code information onto a card.

In the meantime, the employee inserts the keys into a slot, and little brushes inside clean them.

The assembler slips the matching keys onto a ring along with the key-code card to keep them all together.

She installs batteries to power lights in the key grip.

To make a lock to match the keys, the worker refers to the key-code card to select notched brass wafers.

She stacks them in an assembly unit so that the notches in the wafers match the bits cut into the key blade.

She places the lock cylinder above the wafers and activates a spring that lifts them into the cylinder.

She flips the cylinder and removes it from the assembly device, then caps the cylinder, encasing the wafers.

She tries a key and confirms it's a match.

She brushes grease into two niches in the cylinder.

She inserts locking bars into each one.

The grease holds them in place as she slides a steel sleeve over the cylinder.

She tries the key again to confirm the assembly functions.

For extra protection, she encases the cylinder in a hard lock body.

She plugs the open end and secures the metal plug with two pins.

She now inserts bolts in the lock.

In operation, these bolts will be pushed into the brake disc to lock it.

A metal sliding cover protects the key hole when not in use.

The installer adds a plastic mechanism to slide it open and closed more easily.

They now have a completed lock bolt.

They assemble the outer lock body.

The two parts come together to form a slot to fit over the brake disc.

Using a custom measuring tool, the employee confirms that the hole for the lock mechanism is the correct size.

She then slides an applicator for lubricant into that hole.

It releases the lubricant, and she distributes it more evenly.

She slots steel balls into compartments in the lock mechanism.

When the lock is engaged, these balls will protrude and keep it engaged.

She pops the locking bolt into the outer casing.

She permanently secures it with a plastic spring, snapping it into place between the steel casing and the lock.

Another application of lubricant, and the motorcycle brake lock is ready for an alarm system.

The alarm has been pre-assembled at another factory.

It fits into a tray-like compartment of the casing.

With the help of a mechanized tool, she press-fits the alarm to the casing.

She slides a plastic dowel into the lock to confirm the alarm mechanism and gauges.

She replaces the section of the casing that was removed for the alarm installation and secures it with a screw.

She polishes the lock against a revolving wheel with little brushes.

She rubs some oil on it, and the metal gleams.

Now complete, this motorbike brake-disc lock looks pretty, just don't mess with it.


Ice Cream Treats
Wooden Golf Clubs
Aircraft Wings
Car Battery Recycling

Today on "how it's made," ice-cream treats...

Wooden golf clubs...

Aircraft wings...

And car-battery recycling.

Before refrigeration, ice cream was a handmade luxury.

Ingredients went into a mixing bowl inside a tub filled with ice and saltwater.

The salt helped the ice absorb heat, cooling the mixture to below freezing.

In the 1920s, commercial freezers made mass production possible, and the ice cream industry was born.

To make ice-cream treats, you first have to make the ice cream.

It all begins with fresh cream.

The factory stores it in refrigerated silos set just a few degrees above freezing.

The silos feed a high-speed mixer that blends the cream with other ingredients.

The main dry ingredients are powdered skim milk and plant-based stabilizers and emulsifiers.

Stabilizers prevent the ice cream from crystallizing, and emulsifiers allow the mix to bond with air during the whipping process.

The other ingredients are sugar and corn syrup.

After about three minutes of mixing, a pumping system moves the mixture into pasteurization tanks and heats it to 162 degrees for half an hour, killing any bacteria and activating the stabilizers.

Then the factory homogenizes the mixture, a process that breaks up the fat globules, giving the ice cream a smooth texture.

The mixture is cooled, and concentrated vanilla flavoring is added.

Then the concoction is chilled and whipped for about 15 seconds.

Whipping blends the mix with air, transforming it from a liquid to a soft solid.

Without air, the finished product would come out looking like frozen milk rather than ice cream.

The ice-cream sandwich wafers are made of chocolate-cake ingredients.

A filling machine feeds two lines of wafers toward an injection pipe.

Just as two wafers come together, the machine injects a third of a cup of vanilla ice cream in between.

The pipe's head fits the ice cream into a rectangular slab that fits perfectly between the wafers.

All this happens at a rate of 140 ice-cream sandwiches per minute.

As the sandwiches move on to packaging, the filling is still ice cold from the freezing phase, so there is no threat of a meltdown.

The packaging system raises each sandwich into a wrapper, then folds and tucks the ends.

The next machine counts the sandwiches and inserts them into boxes.

Once sealed, the boxes go directly into a storage freezer at minus 22 degrees.

On another line, ice-cream cone production is under way.

A feeder drops prewrapped sugar cones into holders on a conveyor belt.

Sprayers coat the insides with a chocolaty layer, which adds flavor and creates a barrier between the cones and ice cream, so the cone remains crispy until you eat it.

Next, nozzles squirt in the ice-cream filling.

One production line, two flavors.

One row of cones gets vanilla ice cream, the other row chocolate.

Now for a tasty surprise in the cone's core, an injection of liquid caramel.

This factory also makes ice-cream cones with chocolate and strawberry sauce inside.

Next, a chocolate-flavored liquid topping.

Then the crunchy finishing touch, a layer of chocolaty coated puffed rice.

Finally, the cones move under a lid dispenser that applies a wax-coated paper lid to each one.

A heating element instantly melts the wax, sealing the lids to the cone's paper sleeve.

From here, the ice-cream cones go into boxes, then straight into the freezer, ready to take a licking.

Up next, the forgotten art of wooden golf clubs.

High-tech metal clubs rule today's golf courses.

But don't count wooden clubs out of the game yet.

Wooden golf clubs are all about tradition.

Golfers have played with them for centuries.

And some players still prefer the look and feel of these finely crafted clubs.

Go with the grain, and your golf game could be on the upswing.

Each club head starts with a log of persimmon wood, which is a type of ebony.

It's sliced into quarters, and the lower quality center section is discarded.

Each quarter is cut down into a workable shape and size.

Then it's locked into this duplicating machine.

A more sculpted piece of wood, called a "master model," is placed overhead.

A wheel traces the contours of the master model and guides a blade below so that it carves the rough chunk of wood into a duplicate of the master model.

The first master model is swapped out for a more refined version, and, again, the blade below copies the shape.

The duplicate stub is cut off, and it gets a light sanding.

Next, using a spinning cutter, a generous slot is carved into the face of the club head.

Heavy-duty glue is spread in the slot, and then it's plugged with an insert made of rigid plastic.

This reinforcement will protect the club head from the force of the golf ball.

The overlap is trimmed off, and the head is sanded until the plastic insert blends seamlessly with the wood.

Next, a router is used to carve an hourglass shape into the bottom of the golf-club head.

This slot will hold the sole plate, which will add weight and protect the bottom of club.

The club head can't be more than three grams off the target weight.

After factoring the weight of the sole plate that's still to be installed, this club head gets a lead pellet to make it a little heavier.

An extra hole is drilled in case more lead needs to be added later.

Then the lead pellet is press-fit to the club head.

Adhesive is slathered into the slot.

Then the stainless-steel sole plate is installed.

Again, sanding smoothes away any bumps or grooves.

A drill bores a hole in the neck of the golf-club head, and a glue-coated metal sleeve slides into that hole.

Then the neck is tapered with a sanding belt.

A jeweler saw is used to score the face of the golf-club head.

These lines are critical, because they help give the ball spin.

The club head gets a dip in water-based stain that soaks into the wood but doesn't penetrate the metal sole plate.

Then, things get messy, as a pasty substance is rubbed all over the golf-club head, plugging the open pores of the persimmon wood.

It's a crucial step that will insure a mirror finish down the line.

The head is numbered to identify it as a fairway club.

And then the sole plate gets a good scrubbing with steel wool to get rid of any fingerprints.

Five coats of polyurethane are sprayed on.

Next, the glue-covered end of the shaft is pushed into the sleeve and the club head.

The club's weight is fine-tuned with the addition of some pulverized lead into the extra hole drilled earlier.

For a player to hit balls accurately, each club in the set has to feel as if it's the same weight.

So, there's one more weigh-in before this wooden golf club is up to par.

Finally, it's time to hit the links with a club that lives up to tradition.

Coming up, crafting the wings that give us flight.

Aircraft wings provide the lift that takes us to the skies.

They're designed to be very strong and very light.

Producing them requires a strategic balance of old-school production methods and high-tech computer-assisted design.

The wing's frame is made up of three main components, the rear spar, the main spar, and the ribs.

The ribs are crafted from aircraft-grade aluminum.

It's corrosion resistant and has great strength, allowing it to resist extreme wind pressure.

A computer-guided stamping machine punches small holes for rivets and control cables.

It also stamps larger holes to reduce overall weight.

Workers break attachments called microjoints and extract the ribs.

Each rib now goes onto a metal-and-rubber forming die.

A hydraulic press applies 150 tons of pressure, stamping the rib to the die shape.

Using a grinder, workers smooth out the sharp edges left behind by the stamping process.

Then they peel off the plastic film that protected the ribs from scratches.

The factory uses the same process to construct the main spar.

The spars run the entire length of the wing.

It takes even more pressure this time-- 222 tons-- to bend the spars into shape.

That's because this aluminum is three times thicker than that used for the ribs.

To ensure they've aligned the ribs perfectly for riveting, workers push spring clamps into the spar.

These hold the ribs in position.

They hand drill holes for larger rivets and smooth out the sharp edges with a deburring drill.

Then, using a pneumatic riveting gun and bucking bar, they rivet the ribs to the main spar.

A tiny bucking bar is required for some of the tighter spaces.

The completed airframe now goes onto a positioning rack, where it will get an aluminum covering they call the wing skin.

Workers use spring clamps to position the top skin onto the airframe.

They use the same procedure for the leading-edge wing nose.

Once everything's clamped together, workers permanently rivet the assembly.

Meanwhile, welders fuse the wing's fuel tank using an argon gas torch, which contains fewer contaminants than the typical acetylene torch.

They fit the tank into the wing chamber, then secure it by bolting steel belts on to the spars.

Now they position the tank's covering plate and screw it onto the wing.

These holes are for fuel lines and control cables, which run the entire length of the wing.

Finally, the wingtip is fitted and bolted on to the wing.

It's made of a lightweight fiberglass-and-plastic composite.

The completed wing is now ready to be bolted on to the aircraft body.

This wing weighs in at a mere 175 pounds.

But it's certainly no lightweight when it comes to strength.

It can withstand nearly 5,500 pounds of wind pressure.

When we return, turning trash into treasury at a car-battery recycling plant.

Car batteries may die, but that doesn't mean it's the end of the road for their components.

These lead-acid batteries are routinely recycled.

This keeps toxic materials out of landfills and gives those old car batteries a lot more mileage.

This battery may be toast, but it's not trash, because dead car batteries are jump-starting a major recycling industry.

Pallets of old batteries are tipped on to a conveyor belt.

It takes them up into an enclosed machine that has over 30 rotating hammers.

They smash the old batteries to bits, and then a screen filters out the lead-acid paste.

The broken bits of lead and plastic tumble into a vat of water.

The lead and other metals sink, while the lighter plastic pieces float to the surface-- a convenient way to sort and separate the battery components.

Once the plastic pieces have been cleaned, a machine blows them into the back of a truck.

They'll be taken to a plastic-recycling plant and turned into pellets that will eventually be used in the production of new car batteries.

A worm screw now moves the lead and other metals to another part of the plant for further processing.

Remember that lead-acid paste screened out of the smashed-up batteries earlier?

The acid has been neutralized and turned into water.

This press squeezes the water out so all that remains is a lead paste.

It's removed and added to the pile of lead and other metals.

The water from the deacidification process contains some metallic residues, so it's treated with chemicals that cause the contaminants to precipitate, then settle into a sludge on the bottom of the tanks.

Workers sample the water to make sure the particles are settling properly.

They pump out the sludge, then filter the water, which now meets regulatory standards and can be poured down the drain.

The sludge goes into that big pile of lead and other metals.

A few shovels full of refined coal are added to the pile as a processing aid.

Then the battery solids head up a conveyor into a revolving drier.

The metals spend 20 minutes in here to remove any excess moisture.

Then it's into a furnace for 10 hours.

The lead melts into a liquid, and the other metals float to the surface, allowing them to be skimmed off.

The molten lead goes into a steel kettle, where it's mixed with caustic soda.

This cause some remaining contaminants to float to the surface for easy removal.

The liquid lead is now fairly pure, so it's time to pour.

The lead is pumped into bar-shaped molds, and any lingering impurities are skimmed off.

Below, a constant spray of ice-cold water chills the molds, and the lead hardens into bars in just four minutes.

The conveyor winds downward, and the bars are tapped free of their molds.

There's enough lead in one of these bars to make three car batteries.

They'll be remelted and molded into battery components.

And the final product is as good as new...

Proving that recycling can give old car batteries new life while keeping dangerous substances out of our landfills.


Aerospace Fasteners
Cactus Pear Puree
Lab Reactors

today on "how it's made"-- aerospace fasteners.

Cactus pear puree.

And lab reactors  an aircraft must be able to withstand extreme conditions and stress, so it's critical that the fasteners holding the parts of the aircraft together are made to precise technical specifications from high-strength corrosion-resistant materials.

This company manufactures fasteners for all types of aircraft.

These screws and bolts are made of aerospace-grade stainless steel.

It arrives from the steel mill as coil.

Certain fasteners are coated with copper, which acts as a lubricant, and the company further lubricates them with powdered soaps and other chemicals.

This prevents the coil from catching as this drawing machine pulls it through a round die.

Wire from the drawing machine enters this bolt-forming machine.

First, it heats the wire and cuts pieces called blanks.

Each blank then passes through five different dies, each of which progressively shapes it into a bolt.

This t-bolt is made from a different type of high-grade stainless steel that doesn't require extra copper lubrication.

The coil goes through the same process as the smaller bolt we just saw.

However, this bolt-forming machine is much larger and uses four dies rather than five to shape the t-bolt.

All fasteners must pass several quality-control checks throughout the manufacturing process.

In this particular test, the factory measures the bolt's head length and diameter and checks the results against the technical specifications.

When the fasteners come off the forming machines, they have sharp edges called burrs, so they have to go for a spin in a deburring machine.

This one is pretty low-tech but highly effective.

Fasteners made of certain types of stainless steel are sent to an outside plant for heat treatment, which strengthens them.

Fasteners made from copper-lubricated stainless steel soak in a bath of nitric acid for about 20 minutes to dissolve the copper without harming the stainless steel.

Workers thoroughly rinse the fasteners with water, then dry them off by spinning them at high speed.

The final step is to form threads on the body of the fasteners.

Forming threads adds even more strength.

That's because this factory does that using a process called thread rolling.

Rather than use machining equipment, which cuts threads into the shank, a process that removes steel and can weaken the bolt, this thread-rolling machine rolls one bolt at a time between two dies, which forms the thread pattern.

This process doesn't remove any material, and compressing the steel to form threads actually increases its strength and ability to handle stress during flight.

The threads undergo a thorough quality-control inspection.

A technician uses a precision gauge to measure them.

Next, he uses ring gauges.

If the fastener screws into the no-go gauge, the dimensions are wrong.

If it screws into the go gauge, they're correct.

This optical imagining system measures the fastener, analyzes the form, spacing and ankles of the threads, then sends the data to the company's computer system.

That system can trace every single fastener back to the batch of steel from which it was made.

Another quality-control test measures tensile strength, how much pull force the fastener can withstand before breaking.

In yet another test, technicians cut the fasteners into pieces, mount them onto a bake-like puck and polish them, then examine them under a digital microscope.

Among other characteristics, they analyze the steel's grain size and structure.

This type of stainless steel has a high nickel and chromium content, making it resistant to extreme temperatures and corrosion.

Another test assesses how hard the steel is according to an international standard known as the rockwell hardness scale.

Such rigorous testing is imperative for safety as these fasteners are what hold aircraft together.

It's a fruit known by many names-- cactus pear, cactus fruit and prickly pear.

It grows on several species of cacti, which are native to parts of north, central and south america.

Some growers, in addition to selling the fruit, produce a puree, which they sell as a flavoring.

Prickly pear martini, anyone?

Cactus pear fruit is high in fiber and rich in vitamins and minerals.

It's sweet and delicious eaten as-is or as a natural flavoring in foods and beverages.

In the salinas valley in california, the cactus pear harvest begins around late august and continues through early april.

The fruit is ripe when its skin begins turning red.

The harvesters wear thick leather gloves to protect their hands from the thorns and safety glasses to shield their eyes from loose thorns that blow through the air.

Tractors haul the cactus pears to the processing plant.

The fruit first passes over brushes and into a vacuum that removes loose dirt, then through a shower of chlorinated water, which kills off bacteria.

The fruit enters a cold-air dryer for about 5 seconds, then passes through a hot-air dryer for 20 seconds.

The fruit exits completely dry.

A quality-control team removes any with bruises or other cosmetic defects and transfers those cactus pears to the puree line.

The fruit that passes inspection falls into what's called a singulator, a machine that lines them up in single file.

The singulator deposits each cactus pear into a cup on a computer-guided weigh-and-sort machine, which classifies each fruit by size, then applies the grower's price code sticker.

The fruit then travels on the conveyor belt that leads to the padded tub designated for its weight classification.

A worker stationed at the tub packs the cactus pears into a lined shipping box.

Another worker removes any less-than-perfect fruit that managed to slip through the previous checks.

Those also go to the puree line.

On the puree line, the dumper drops the cactus pears onto a conveyor-belt system, which transports them to the crusher.

The machine crushes the fruit, separating the skins and flesh, mashing the flesh into puree and extracting the sweet magenta-colored juice.

From the crusher, the pressed skins drop onto the vibrating shaker while the puree and juice flow through it into a tank below.

The shaker separates any puree still caught in the skins.

The skins drop into a bin and are hauled off to be used as compost or sold as animal feed.

Once the tank is filled to capacity with about 400 pounds of puree, a pump transfers it to a large hopper.

A worker releases puree from the hopper to the finisher.

The finisher's fine screens trap the seeds while letting the puree pass through to a holding tank below.

The seeds are sold to businesses that press them into oil for cosmetic and hair products.

From the holding tank, the deseeded puree passes through a second finisher with even finer filters.

Then it flows into a tank for pasteurization, which kills off any remaining bacteria.

The puree is finally ready.

A worker fills a drum, which is double-lined with plastic bags.

She draws four 1-cup samples from each drum for quality-control tracking.

Once a drum contains 400 pounds of puree, the worker zip-ties each bag separately, closes the drum with a lid, safety-seals the lid with a lock, then puts the drum in the freezer.

The cactus pear puree is sold frozen to the food and beverage industry, which uses it to flavor many products, from ice cream, sorbet, and gelato to flavored water, wine, tequila, and brandy.

Lab reactors are vessels of discovery.

Inside these enclosed glass systems, chemical and biological reactions happen.

Useful for developing many products, including medications like cancer drugs, they can also be used to produce these products on a small scale.

A lab reactor is basically a sophisticated blender.

During mixing, it also heats or cools ingredients to start a chemical reaction, and there are ports for attachments like a condenser.

Making lab reactors starts with solid glass rods.

The rods are sometimes a bit crooked, so a worker heats and moves them across rollers to straighten them.

Grinding wheels round their shape to more precise contours, and a wet sanding smooths the surface.

The operator measures the outer diameter of each rod.

A worker heats one end of the rod and forms a rim using a special tool.

He applies dabs of liquid glass just below the rim.

This creates nubs for properly situating the blade hub on the main shaft.

To make the reactor's inner wall, he scores a wide glass tube and exposes the score line to a flame and then water.

Another worker heats the top end.

He supports the glass with a wide paddle until it's malleable enough to shape.

A forming tool gives it a wide lip that will serve as the opening of the reactor.

He aims a flame at the newly formed flange to smooth out any imperfections.

He slides a larger glass vessel over the flask, then fuses them at both ends.

This creates a hollow jacket through which liquids will be pumped to heat or cool the contents of the flask.

A different worker cuts another glass tube to length.

He scores it lightly and again exposes it to fire and water to break it along the etched line.

He shapes the tube into a port for the outside of the reactor jacket.

He'll make two of these ports.

They'll be used to circulate heating and cooling liquids.

Using the torch, a worker softens a spot on the reactor jacket.

With tweezers, he pulls away the softened glass, creating a hole for the port to be installed.

After inserting a ceramic holder in the port, he fuses it to the hole on an angle.

Once the seam solidifies, the port will be an intrinsic part of the lab-reactor vessel.

Abrasive wheels grind another glass tube to make it perfectly round.

This tube will be part of a drainage valve.

An employee then begins work on the rest of the drainage valve assembly.

He forms an internal thread for a plug.

And after cutting it shorter, another worker creates a flange on the other end.

He burns a hole in the side of the valve tube.

The drainage tubing, now also cut shorter, is ready to be attached to the rest of the valve.

He heats the connecting points, and they melt and meld together.

Since we last saw it, the reactor vessel has received a base.

A worker burns a hole in that base and fuses the drainage valve onto it.

Another employee then places the reactor vessel in a special fixture and checks that it sits level.

She adds specific amounts of water incrementally, beginning with 2 cups.

She draws a line on the outside of the reactor vessel to indicate the amount inside.

This will provide a reference for affixing a scale.

Using the markings as a guide, she applies the ceramic scale.

They'll become part of the glass when the vessel is baked and slowly cooled.

Stay tuned for a lot more, as this lab reactor comes together to create a stir.

Making a lab reactor is done for science.

Precision is important because these reactors will be used to develop new drugs, cosmetics and a range of chemical materials.

They can also serve as little factories, producing small batches of products.

A lab reactor needs sturdy impeller blades to generate an effective chemical reaction.

An automated milling tool cuts a notch in a disk made from strong chemically resistant plastic.

Another system carves screw threads into a hub made of the same material.

A tool bores a hole in the center for the insertion of what's called the agitator shaft.

The operator smooths the threads with fine sandpaper and then assembles the blades to the hub.

Next is the condenser.

It's an attachment through which vapor will travel to be transformed into a liquid.

The worker twists the softened glass tube around a rod to form the coil.

Another worker inserts a linear glass tube in the center of the coil.

She melts glass near the bottom to seal the center tube to the coil.

Moving to the top, she heats the glass and, with tweezers, pulls a bit from the end of the coil to pry it open.

With a pick, she opens it up a little more.

She uses a graphite reaming tool to shape the glass opening into a more flared profile.

The condenser body takes shape, and the worker forms a joint on the end.

He inserts a standard joint to test the fit.

The coil can now be inserted into the condenser body.

Another worker fuses the condenser wall to the coil and burns holes in the glass wall to connect hose attachments.

She exposes the seam to a less focused flame to bring down the temperature slowly.

The next worker creates a joint for the lower end of the condenser.

This joint will be used to connect the condenser to the reactor.

Once the basic taper profile has been achieved, grinding tools size it more precisely.

When the connector joint has been cut to length, the worker attaches it to the base of the condenser.

Another glass fabricator makes more joints, one of which will connect the condenser to the reactor lid, or head, as it's known in the industry.

He keeps the glass tube long for easy handling and then cuts it to the correct length.

The worker now seals the center joint to a hole in the reactor lid.

He burns holes in the reactor head for other connectors.

As the glass balloons up, he pulls it away to fully open the hole.

With all the connectors fused to the reactor head, a worker grinds the base of its flange against an abrasive wheel to make it perfectly even.

An employee then applies decals to the head.

These indicate the brand and the connector size.

The decals will be baked into the glass during its final heating.

He places all the parts in the annealing oven.

The temperature gradually ramps up to 1,040 degrees fahrenheit and slowly cools.

This final annealing removes internal stresses and strengthens the glass.

An inspector scrutinizes the head with a tool to confirm that the connector joints are in proper alignment and positioned at the correct angle.

Workers install the vessel on a stand, insert the shaft and blades, attach the head and connect the condenser.

To simulate how it works, a technician pours liquid into the reactor.

He adds colorful plastic solids that will show up better for this demonstration.

He activates the impeller blades.

These blades are designed to lift solids to the top, and they do that effectively.

He also runs cooling liquids through the condenser.

In practice, the cool coil will cause vapors from the vessel to convert back to a liquid.

This lab reactor is now ready to be a lifesaver.


Today on "how it's made"...

Honey...

Fiber optics...

Bricks...

And pipe organs.

It's winnie the pooh's favorite treat.

It's sweet and sticky.

And it's produced by an industrious insect, whose miniature society is one of the most sophisticated in the animal kingdom.

It all begins in a field, where worker honeybees suck nectar from flower blossoms, such as clover.

They store it in their honey sack, then return to the hive, where other worker bees suck it out and chew it, breaking down the nectar's complex sugars into two simple sugars called glucose and fructose.

The bees then deposit the nectar into the cells of the wax honeycombs they've built.

They fan it with their wings until most of its water content evaporates in the warm air of the beehive.

What's left is thick and gooey honey.

The bees then cap each honey-filled cell with beeswax.

That's when the beekeeper steps in.

Bees will sting if taken by surprise, so the beekeeper sprays the hive with smoke from burning pine needles, a scented warning that foreigners are about to enter the hive.

Inside the hive are wooden frames hanging side by side, each holding a honeycomb.

A hive can house hundreds of thousands of bees, all descendants of the prolific grand pooh-bah of beedom, the queen bee.

She's the big one in the middle.

The queen bee lays up to 2,000 eggs a day, creating the work force needed to feed and protect the colony.

But the beekeeper tricks the colony's defenders.

He replaces the hive's cover with a device called a bee escape, that smells like cherries.

Bees dislike the scent, so most fly to the bottom sections of the hive.

Another warning spray, and the beekeeper removes the bee escape.

Now he can escape with the honeycombs.

Inside the honey factory, they put the honeycomb frames on what's called an uncapping machine.

Like a razor, it shaves the wax caps off the honey-filled cells of the combs.

They scrape off the remnants manually.

Then they set the frames on another machine called a honey extractor.

It spins the honeycombs until all the honey is forced out of the cells.

Afterwards, they filter the honey to remove any pieces of wax capping that slipped through.

Then the honey is ready for bottling.

Some beehives contain smaller frames, designed to produce honey that isn't extracted from the honeycomb.

Workers remove the frame and cut the honeycomb into pieces as is with a heated knife.

That seals the wax around the honey inside.

You eat it, wax and all.

The beeswax lining of the honeycomb goes to make candles, furniture polish, lipsticks, and other products.

When producers have more liquid honey than they can sell, they simply let it granulate, develop sugar crystals, and turn hard and white.

Then, when the orders come in, they return it to its original liquid form by heating it to 130 degrees.

They vacuum-clean the jars...

Then fill them.

One beehive can yield up to seven pounds of honey in a single day.

That's much more than the bees need for themselves.

The surplus is what we end up eating.

Honey production today is both efficient and humane.

For centuries, the only way to harvest honey from hives had been to kill the bees.

Then, in 1851, an american beekeeper invented a way to get the honey, yet spare the bees.

His method, with the removable honeycomb frames, is the one we still use today.

American researchers have invented a plastic that repairs itself when broken.

Just apply heat--  a simple hair dryer will do-- and the break automatically mends itself.

This could solve a longtime problem in electronics, because when components heat up and cool down, they weaken the plastic around them.

Every time you talk on the phone or go on the internet, what you say or type travels to its destination through fiber optics, voice and data gets transmitted via pulses of light through hair-thin glass fibers.

Those fibers start out as large glass tubes.

First, workers unwrap the tubes.

Then they submerge them in a corrosive bath of hydrofluoric acid that removes any oil residues.

Then they set a tube into each end of a lathe.

As the tubes spin, they're heated with a hydrogen-oxygen flame.

When the glass turns white, it's getting close to hitting peak temperature.

At about 3,500 degrees, the two tubes fuse together.

They put this new, longer tube onto another lathe.

As the tube spins, they inject a mixture of chemical gases inside, while a traversing burner heats everything up.

The gas mixture contains liquid forms of silicon-- an abundant chemical element found in nature-- and germanium, a chemical element similar to tin that's used as a semiconductor in transistors and other electronic devices.

As the gases heat, they undergo a chemical reaction that leaves a white soot on the inside of the glass tube.

The heat fuses the soot, forming what will eventually become the core of the optical fiber.

The glass tube itself will form the fiber's covering.

When there's enough fused soot, they turn up the heat until the soot itself turns into glass.

Then they heat the glass tube enough to soften it, and to soften the new glass inside.

The intense heat eventually makes the tube collapse on itself to form a solid rod.

The internal structure of the optical fiber has been achieved.

But it's in the form of a big, bulky rod called a preform, so the next step is to thin it out.

First, they excise the preform from the uncollapsed section of the glass tube.

Then they install it vertically into the drawing tower, which will draw out the final shape.

The drawing tower's oven heats one end of the preform to 3,600 degrees.

The glass softens.

Gravity helps pull it down, like honey dripping from a spoon.

Then, using a glob of glass as a weight, they stretch the soft glass and keep stretching it until they've formed a thin glass fiber.

A series of pulleys measures the tension on the fiber as it's being drawn.

A special monitor makes sure the fiber's precisely the right diameter-- just .

005 of an inch.

Then the fiber passes through u.v. lamps that bake on an acrylic coating to protect against dust and other contaminants.

Finally, the fiber is rolled onto a drum.

From here, it's either shipped out as is or put into a cable.

Fiber-optic cables are expensive to produce, but they're smaller and lighter than traditional copper cables.

They carry more information and need fewer repeaters to keep the signal from deteriorating.

And, unlike copper cables, they're immune to electromagnetic interference.

They're also hard to tap without being detected.

And all this is made possible by a complicated process based on a very simple principle-- light traveling through glass.

Those three little pigs knew what they were doing when they built that brick house.

Not only are bricks wolf-proof, they're also fireproof, pest-resistant, and weather-resistant.

No wonder they're one of the world's oldest building materials.

Bricks are often made of shale, a lightweight rock that splits easily into thin layers.

Quarry machines dig 16 inches down to expose the shale to the elements for 2 years.

This weakens it, making it easier to process once it gets to the factory.

A 4-foot-high stone wheel with a steel tire grinds the shale into powder.

It grinds up 50 tons of shale per hour.

A screen sifts out any pieces that need more grinding.

The powder goes to the pug mill that mixes it with water.

This makes a thick paste that will go through the extrusion machine next.

The extruder forces the paste through a rectangular opening to form one long, continuous piece called a slug.

At the same time, it shaves off the crustier top layer to expose what will become the face of the brick.

If this gray shale mixture is fired as is, it will naturally produce a red brick.

To engineer a different color, they coat the slug in sand mixed with an oxide mineral such as zinc or iron.

Next, they texture the surface with a textured roller.

This is just one of many popular designs.

Then a large knife comes down like a guillotine and slices the slug into 5-foot lengths.

You might be wondering where those three holes came from.

Well, remember how the paste goes through the extruder to form the slug?

Inside are three pins.

They make three holes designed to decrease the brick's weight.

Out of each 5-foot length, they cut 20 3-inch bricks.

The ones on the ends are uneven, so they go back into the mix to make new slugs.

Next comes the delicate job of stacking these newly minted bricks-to-be.

A machine first separates them.

Then, using inflating bags, it grasps them, raises them...

Then stacks them.

Meanwhile, the water in the bricks is starting to evaporate.

To hasten that process, the bricks go into a dryer for two days.

The dryer gets its hot air from the heat generated by the kiln, where the bricks go next for firing.

The kiln is really a giant oven.

It bakes the bricks at 1,900 degrees.

1 1/2 days later, the bricks are ready.

The transfer machine takes them out of the kiln.

But before they go to market, a technician does a quality check.

He weighs and measures a sample to see if it meets the design specifications.

Bricks are supposed to absorb some water, but not too much.

Yet, if they repel water completely, they'll also repel the wet mortars the masons use to stick the bricks together.

So to test absorbancy, the technician breaks a brick in half.

He weighs it before and after soaking it in water for 24 hours.

By comparing the weights, he can see how much water the brick has absorbed.

Once the batch gets the okay, they stack the bricks into cubes of 500 to 600.

Each brick weighs 5 1/2 pounds, so each cube weighs in at about 1/4 ton.

Brick is one of the sturdiest building materials around.

It doesn't rot, fade, warp, or dent the way some other materials can.

Bricks are also energy-efficient.

They absorb heat to help cool your house in the summer and hold heat to help keep it warmer in the winter.

The music it makes is as complex as it is majestic.

The pipe organ is one of the largest and most technically sophisticated instruments.

Building one is an incredible feat of engineering and craftsmanship.

Early man discovered he could make music by blowing across hollow reeds of different lengths.

In ancient egypt, an engineer devised what would later become the basic technology of the pipe organ, a steady airflow without mouth-blowing while controlling the air to each pipe to create different notes.

By the middle ages, the pipe organ was a fixture in churches throughout europe.

Johann sebastian bach composed his greatest works for organ while working as the musical director of a church.

a concept artist creates the design.

The design then goes to a draftsperson, who prepares the technical drawings.

The organ's pipes are made of a mixture of tin and lead.

Tin-- the harder metal--  gives brightness to the sound, while lead--  the softer metal-- gives it warmth.

Artisans pour the molten alloy into a tray, then draw it out to form a sheet.

As the sheet cools, the two metals react to each other, creating spots.

The sheet goes into storage to give the alloy time to stabilize.

Two to three months later, it's ready to be formed into organ pipes.

First, they cut pieces of metal in the shape of each pipe using templates and large rulers.

Then they roll each piece using a mandrel.

The larger the organ, the more pipes it has.

Pipes are grounded in sets of 61, corresponding to the 61 black-and-white keys on the keyboard.

And elaborate organ can have more than 10,000 pipes.

The pipemaker carefully seals the body of each pipe by hand, using tin solder.

Next, he solders the body of the pipe to the foot and languet.

The languet is the part that produces the pipe's sound.

The process of giving a specific sound to each pipe is called voicing.

This work is done by a trained musician called a voicer.

He enlarges the mouth of the pipe, called the cut-up, until it's approximately 1/4 of the width across.

He adjusts the pipe some more, blowing air through it to judge how to further refine the tone.

Next come the windchests, also called the soundboards.

These are the large wooden boxes filled with air on which the pipes stand.

Under each pipe is an air channel covered by a valve.

The valve is made of leather and sits on a wooden board.

When the organist pushes a key on the keyboard, the corresponding valve drops down like a trapdoor, releasing air into the pipe to play the note.

they glue the valves to the windchests one at a time, using animal glue.

It's suppler and dries faster than synthetic glue.

The valves are connected to the organ's keys mechanically by long tracks of cedarwood or by electrical wiring.

The electric signal triggers electromagnets to cause a sudden air depression, making the trapdoor valve drop down and let the air in.

The console is the organ's brain.

It contains all the controls for the keys and sets of pipes.

The organ's white keys are made of linden wood covered with bone, the black keys of ebony or rosewood.

An artisan adjusts the keys using a weight.

When the weight rises, the tension is just right.

The console, keys, and all the other components are finally put together in the assembly room.

After testing, they disassemble the organ and ship it to its destination, where it's reassembled.

The voicers come on-site to perform what's called tonal finishing.

They check and adjust each pipe according to the acoustics of the room.

This process can take many months for a large and elaborate organ.


Leather Briefcases
Crop Dusters
Corn Whiskey
Drag Racing Clutches

Briefcases come in many styles today.

The classic type is a rigid rectangular box made up of two hinged sections that close together.

It's often referred to as an attaché case because it was traditionally the type of briefcase used in diplomatic circles by cultural or military attachés.

These luxury attachés are entirely handcrafted, made from english bridal leather, a fine leather traditionally used for horse saddles.

The cutter lays out patterns for the various parts, then trims around them.

Leather, being an animal hide, naturally has scars and blemishes here and there, so he's careful to select blemish-free areas for use as the main surfaces.

Next he uses a punch press to cut out what are called foundation boards, which will reinforce the leather.

At this point, an expert leather craftsman takes over.

He positions each foundation board on the leather.

Using a tool called a bone folder, he marks where the leather will fold over each board.

Then he coats the boards with leather-bonding glue...

And positions them along the fold lines he marked.

With a tool called a sleeker, he pushes out air pockets and excess glue.

This ensures a thorough, wrinkle-free bond.

Next, with a tool called a stitch marker, he perforates the edges of the leather.

This ensures the stitching will be straight and evenly spaced.

It also sets the angle of the stitches, essential for both aesthetics and durability.

Now he bevels the leather.

This leaves what's known as a raw edge, which he then colors and seals with a reddish stain that highlights the tan-colored leather.

The attaché case frame is made of steel.

The craftsman uses contact adhesive to mate the frame to the foundation board and leather.

Now he can sew the leather.

He inserts an awl in each stitch hole to clear a path through the leather and boards.

Then he passes two strong saddle-stitching needles in opposite directions, pulling the pure-linen threads waxed with tallow.

Next he rivets in place two traditional-style locks made of hand-polished brass.

Then he constructs the handle by sewing several layers of leather around a piece of steel.

The handle has a raised rib on the top and bottom.

These risers, as they're called, make the handle comfortable to hold.

He uses the bone folder to fit a piece of finishing leather snugly against the risers.

He glues finishing leather around the handle ends...

Feeds each end through a brass ring...

Then folds over the ends to lock in the rings.

Then he wraps the rest of the leather under and hand-stitches all around.

The rings attach to brass handle plates, which he secures from the inside with washers and bolts.

Next he glues in the lid-pocket assembly...

An all-leather organizer that contains pen loops and pockets for files and business cards.

Finally, he lines the bottom section with sheepskin leather that's been coated with a semigloss glaze so it can be wiped clean with a damp cloth.

The outer leather is strong and weather-resistant because it's been tanned with natural plant and tree extracts, then conditioned by hand with fish oils and lanolin, centuries-old techniques they still use to make luxury leather goods today.

Crop dusters are airplanes specially outfitted for aerial spraying.

Farmers use them to seed fields and apply pesticides and fertilizer.

The aquaculture industry uses them to feed fish, and emergency crews fly them to spread retardant on forest fires and dispersants on oil spills.

Depending on its size, a crop duster can carry up to 2,700 liters of liquid or dry material.

The plane is designed to be able to swoop down low to accurately cover the target spray area.

At the factory, they manually weld lightweight aircraft-grade steel tubes to construct the frame of the fuselage.

Next they use spring-loaded fasteners to affix aluminum panels to the sides.

An anti-rust coating turns the aluminum golden color.

All the plane's aluminum parts require this coating, because many of the chemicals crop dusters carry are corrosive.

The tank that holds those chemicals is called a hopper.

The factory molds it out of many layers of fiberglass, which is deliberately transparent.

This enables the pilot to see at a glance roughly how much chemical remains.

Inside each of the plane's wings is a row of vertical supports called webs.

To make each web, they lay a soft aluminum sheet on a mold, place a rubber mat on top, then load the assembly into a press.

A built-in water bag distributes the pressure evenly.

This helps form the aluminum sheet perfectly.

Next they soak the web for a half-hour in molten sodium chloride at more than 900 degrees fahrenheit.

Then they immediately submerge the web in lukewarm water.

This triggers a molecular reaction that hardens the aluminum.

Each wing contains 32 webs.

Technicians line them up in an assembly fixture in between the wing's horizontal beams called spars.

Once they've riveted the webs to the spars, they cover the structure with aluminum panels using spring clamps for now.

The panels have holes in them to allow regular inspections of the structure inside.

After riveting the panels, technicians screw covers onto the inspection holes.

They also seal the seams between panels with liquid rubber so chemicals can't penetrate.

Next they install the engine and the propeller, which ranges from 750 to 1,400 horsepower.

The prop has from three to five aluminum blades.

Now the equipment that releases the chemicals from the air.

For spraying liquids, they hook up horizontal pipes lined with spray nozzles called booms.

To apply dry chemicals or disperse seed, the flight crew detaches the booms and installs a large stainless-steel funnel called a spreader under the plane's belly.

At release time, the pilot opens a door at the bottom of the hopper, enabling the wind to draw out the contents through the spreader.

To spray liquids, a wind-driven pump moves the hopper contents to the booms.

Technicians now assemble and install the instrumentation panel.

To fill the hopper with liquid chemicals, they connect a pump to a valve on the side of the crop duster.

For dry chemicals, they just lift the hopper's lid and fill 'er up.

More than three centuries ago, american bootleggers made corn whiskey by moonlight to avoid being detected by the tax authorities, and so this whiskey became known as moonshine.

Today, that whiskey has emerged from the shadows of history and is produced legally, but people still call it moonshine.

It was the nectar of outlaws-- clear, fresh corn whiskey that's 50% alcohol, and centuries later, it still has a potent appeal.

In virginia, they still make this whiskey the traditional way, allowing corn to germinate in a process called malting.

They mix a small amount of the malted kernels with regular corn in a big tank, then funnel the mix into a mill.

Inside this mill, automated hammers grind the mix to a cornmeal consistency.

This frees some of the starch and exposes it to enzymes from the malted kernels.

Those enzymes convert the starch to sugar.

They'll use some of this ground corn to make a big batch of yeast.

They add it to water in a tank and boil it until it becomes a thick soup.

Once it reaches the desired consistency, they allow it to cool to room temperature.

They add yeast and blow air into the mix to help the yeast grow, making this one big batch of liquid yeast.

In another tank, a ton of corn is being blended with water and boiled.

This breaks down more of the starch, converting it to sugar.

Once cooled, they pump the mix and the liquefied yeast into the fermentation tank.

Over a period of four days, the yeast turns the sugar to alcohol.

The process also generates carbon dioxide, which is vented into the atmosphere.

Every so often, the brewmaster scoops up some liquid and scrutinizes it.

If it looks too thick, the conversion of sugar to alcohol is not yet complete.

But when the viscosity is just right, they pump the batch into a big copper still.

It's just like the type used to make moonshine in the backwoods centuries ago.

They heat it to 82 degrees celsius.

At that temperature, alcohol will boil, but water will not.

As the alcohol boils off the mix, it's recovered through a condenser.

The recovered liquid is 80% alcohol.

Talk about a stiff drink.

So they add water to cut it down to about 50%, and then it's ready to bottle.

To make a darker whiskey, they steep it with what looks like a big tea bag.

It's actually wood chips wrapped in cheesecloth.

The whiskey absorbs flavor and color from the wood over a period of about two months.

When the whiskey takes on a golden hue, they transfer it into oak barrels.

They allow the whiskey to age for two years in a hot room.

The heat causes the whiskey to expand, causing it to absorb the flavor of the wood, but the pressure can also cause cracks in the barrels, so the brewmaster routinely checks for leaks.

After the whiskey has aged, they adjust the alcohol content by adding a little water.

The water is always softened and filtered to remove minerals that could affect the whiskey's taste.

At the bottling station, machinery pumps the whiskey into the containers.

There's no spillage, and not a drop goes to waste.

Machinery then twists on the caps for an airtight seal that preserves the aroma and flavor of this old-fashioned corn whiskey.

At the next station, robotic arms grab labels, apply glue to them, then press them onto the bottles.

It has taken a combination of down-home methodology and modern technology to prepare this old-fashioned american whiskey for market.

And whether it's aged or fresh, this historic whiskey is sure to set the taste buds ablaze.

This clutch is not for the family sedan.

It's a racing clutch designed for a car with an 1,800-horsepower engine.

Without this kind of heavy-duty clutch, there would be no way to transfer that much power to the wheels, and the racecar would be going nowhere fast.

Racecars use a manual transmission to transfer power to the wheels, so a good clutch is behind every win.

Production starts with a flywheel, which connects the clutch to the engine.

Computerized cutting tools shape this aluminum part, then move on to carve the cover plate for the clutch.

They trim its perimeter to give it the correct profile and reduce its weight.

Next they use a bolt with an industrial diamond tip to level the surface of an iron friction disk.

This will allow for better contact with other parts of the clutch.

There are typically two to three of these friction disks in a racing clutch.

The clutch disks will ride against this steel insert, which they position on the flywheel.

The technician applies locking compound to bolts, then uses them to attach the insert to the flywheel.

Here, the technician sets the bolts to a precise torque.

Next he uses this grinder to flatten the surface of the steel insert, again for better contact with the clutch disk.

These bolts will anchor the clutch assembly to the flywheel.

They're called stand bolts, and there are six.

Here, they sculpt titanium cylinders to act as stands for the bolts that were just installed in the flywheel.

Titanium is strong and lightweight, which is important because of the huge amount of energy the clutch must transfer.

The technician places a stand over each bolt, then arranges the clutch disks and a floater plate on the flywheel.

He presets the height of the stands.

Then he prepares the pressure-plate assembly.

He presses aluminum cups into holes in the cover.

These cups will hold springs that will be used to change the pressure of the clutch pack, but he holds off on inserting the springs in the cups.

First he installs a series of levers on the cover plate.

He slides pivot pins into each lever.

These pins will enable the levers to compress and decompress the clutch pack.

He applies lubricant to adjuster screws for the clutch springs, then threads each one into an aluminum casing.

He inserts an assembly in each cup, followed by a heavy-duty spring.

He now installs the pressure ring on the underside of the cover.

When the driver releases the clutch pedal, the levers cause the pressure ring to compress the clutch pack.

That action transfers power from the engine to the transmission.

He now slips the pressure-ring assembly over the stand bolts and secures it with nuts.

He adjusts each stand with a socket wrench, then checks the height.

He measures the tips of the levers to confirm they're even and makes any necessary adjustments.

He pushes the levers to test this clutch, and the pressure ring responds as it should, creating the necessary pressure on the clutch pack.

Finally, a certification sticker and some strapping to secure it for shipping.

At the track, this clutch will be serviced between every run, and if it's operating at peak performance, a win could be just down the road.


Today on "how it's made"...

Bacon...

Snowblowers...

And a special 2-part report on the making of the rolls-royce.

When it comes to breakfast, bacon is one of our favorite side orders.

Its popularity actually goes back centuries to the days when people cured and smoked meats in their own homes.

But, today, a quick trip to the store, and anyone can bring home the bacon.

Bacon is now processed and even precooked in factories.

It all starts with a load of pork bellies.

They're tossed into a big tumbler.

The action softens them, so it will be easier to remove the skins.

Each pork belly goes skin-side down on a conveyor belt.

This conveyor takes the pork bellies to a long, automated blade that slices the skin away from the meat.

The skins drop onto another conveyor belt to be processed into pork rinds.

Meanwhile, the meat pieces head toward a flipping device that turns them backside up, so workers down the line can trim off any remaining pieces of skin.

Next, they mix up a brine solution which will cure the pork.

Salt is funneled into a tank of water.

It's mixed thoroughly until the salt dissolves.

Then, liquid smoke and other flavorings are added.

The pork bellies now pass under an injector head.

Its needles repeatedly inject a curing solution into each pork belly.

A metal hanger, called a comb, is pressed into each of the pork bellies so they can be hung on a rack.

Then, it's into the drench cabinet for a shower of liquid smoke.

As liquid smoke bombards the meat, it adds flavor and color to the surface.

The pork bellies are transferred to a big oven.

They'll cook for five hours at a low temperature.

That allows the flavoring to permeate the meat.

Now it's into a blast freezer for a quick chilldown, then into another cooler for a couple of days.

The cooling firms the meat, which makes it easier to slice.

The pork bellies head to a sizing station, where their sides get a quick trim.

They also pass under a metal detector to confirm that no piece of the metal hanger has gotten lodged in the meat.

After that, the pork bellies are stacked and wrapped, then stored in the freezer until they're ready to be sliced into bacon.

This is called the slice line.

Here, workers load the meat slabs into chutes.

The chutes sway back and forth over a blade, which slices the meat into bacon-sized pieces.

The bacon falls neatly onto a conveyor belt.

Another conveyor belt rolls over the bacon slices to secure them for cooking in a browning microwave.

As the fat cooks off the bacon, it drain into a trough.

These drippings will be used to make gravy and pet foods.

The cooked bacon now exits the microwave oven and comes under the watchful eye of an inspector.

She discards slices that are broken or not up to par.

These wheels then roll the brown bacon slices onto parchment paper.

A tiny electronic eye keeps track of the number of slices.

Finally, the bacon is stacked for packaging.

Now, that's a job well done.

Time to put the coffee on and scramble up some eggs.

When we return, making the machine that makes snow shoveling obsolete.

Snowblowers first came on the market in the 1950s, and before long, this alternative to shoveling really took off.

Today's machines come in a range of sizes, from smaller models with 26cc engines to 50cc machines 3 feet wide for plowing through even the deepest snow.

At the heart of a snowblower are rotating blades called augers.

The left and right augers spiral in opposite directions in order to move snow toward the middle.

There, a fan called an impeller swallows the snow and blows it out a chute.

Each auger starts out as a blank-- a partially formed steel disk a little less than 1/8 inch thick.

This press finalizes the shape with about 200 tons of pressure.

The bigger the snowblower, the bigger its augers.

The press forms the left and right augers at the same time.

Then, a blast of air ejects them onto separate conveyor belts.

Next step, workers take a steel tube, called a hub, and mount it upright on an assembly jig.

Then, they take an auger and center it on the hub.

The hub and auger then travel down a conveyor belt to a robotic welder.

The robot fuses the two pieces into a single unit.

Elsewhere in the factory, workers construct the steel housing that will encase the augers.

This housing consists of four parts-- a cup to hold the impeller, a backpiece with a hole for the cup, and two side plates.

This bar aligns the pieces in a holder.

First, everything turns upside down so the robot can access the back and weld the cup to the backpiece.

Then, it flips right-side up again, and the robot welds on the side plates.

Total construction time-- 55 seconds.

The housings now undergo an electrostatic paint process.

Powder paint laced with a positive electrical charge is drawn like a magnet to the housings, which have been negatively charged.

Workers inspect the coat of paint and do any necessary touch-ups.

Then, the housings spend 15 minutes in an oven which bakes on the paint.

In another part of the factory, workers have bolted a gas-powered engine to a painted steel frame.

Inside this frame, they assemble the transmission-- the gear system that transfers power from the engine to the snowblower's wheels and augers.

After bolting on the impeller, that black component in the back, they attach a large, steel axle to the transmission-driven sprocket.

Then, they slide the now-painted auger and hub units onto this axle.

Now the housing arrives.

Workers bolt the auger assembly into it.

The impeller slides into the cup that's centered at the back of the housing.

Then, they screw the housing to the transmission frame.

The last component is the snowblower's handle, where the control panel is mounted.

There's a lever for selecting different speeds and clutch levers that can be locked down to direct the wheels and augers.

There's also a headlight so that you'll be visible to oncoming cars while clearing snow at night or on a snowy day.

And, of course, there's a lever that lets you choose the direction you want to blow the snow.

Coming up, behind the scenes at one of the most luxurious production lines in the world.

If you have one of these cars, you may also have a chauffeur and a pretty big bank account.

This rolls-royce costs more than an average house in some cities.

But a house is just a place to live, and you can really live it up if you have a car like this.

Since the company's inception in 1906, rolls-royce has been going the extra mile when it comes to perks and performance.

For many people, the car they drive is a measure of their personal success, and you don't get much more successful than this.

Each rolls-royce starts with a hand-welded aluminum body shelf that's rigid yet lightweight.

Then, workers handcraft the components for a lavish interior.

This gadget stitches together sheets of wooden veneer.

The veneers have been cut from the same piece of wood.

Workers match the grain so each side is a mirror image of the other.

The technique is called book-matching, and the look is seamless luxury.

There are 40 or more solid, wooden parts in the interior of this rolls.

These are for the dashboard.

Each of these parts is hand-finished.

Workers meticulously polish the wood with a special paste that enhances the grain.

A lacquer job puts a shine on the woodwork.

Inspectors scrutinize the leather for any natural defects and mark them in white.

They'll work around those blemishes so no imperfections will be visible on the car's upholstery.

It will take as many as 18 hides to make all the seats, panels, and consoles.

Leather pieces are carefully stretched onto various components.

The fit is set with a dryer.

Ensuring the sewn leather parts conform to all the curves and crevices on the door panels can be tricky.

But these workers, some of them former saddlemakers, are experts at the job.

They mount the upholstered leather parts to the car's interior and secure them tightly with screws.

They fit handles and control panels into the tailored slots.

Next, they attach switches, wiring, and other controls to the instrument panel.

This framework has been crafted from a single piece of magnesium so there aren't any squeaky joints.

The impressive radiator grille has a purpose besides bringing in cool air.

It houses the rolls' signature hood ornament and its automated platform.

Workers test the platform to confirm that it rises and retracts smoothly.

Then, they mount it under an opening at the top of the grille.

They check the spacing around the opening's cover to make sure there's enough room for things to run smoothly.

The rolls-royce mascot is called the spirit of ecstasy.

With the mascot now locked in proud position, workers are ready to assemble the car's mechanics.

So stay tuned.

This rolls-royce is looking good.

The body shell has the long lines of luxury.

It's been equipped with flawless leather upholstery and elegant wooden paneling.

Plush and posh, this car is now ready for some serious engine power.

It's bumper-to-bumper opulence at this factory as these cars are lined up to receive their engine components.

Workers install soundproofing material on the floor of the car to muffle engine noise.

Then, they run the wiring loom along the length of the vehicle.

This is the car's nervous system.

It transmits huge amounts of information that help run the engine, transmission, even the car's entertainment system.

Next, the engine and transmission system are hoisted onto a metal platform.

This v-12 engine has 400-plus horsepower.

Workers complete the assembly and make some final adjustments.

Then, it's time for the engine and car body to become one.

They call this the marriage.

The platform rolls the engine down an aisle to be joined with the awaiting car body.

Then, it lifts the engine into the cavity of the car.

It's secured with bolts.

Then, the platform moves away to get the next engine for the next car.

Workers double-check the installation and mark parts with yellow to confirm that they've been fitted.

The engine is now installed, but there are still a number of steps before the car is complete.

The instrument control panel is mounted to the dashboard and gets an upholstered leather cushion.

Veneer paneling is fitted around the dashboard controls.

And the headlining, made of cashmere and wool, goes into place.

Workers check the hydraulic cup holders in the rear of the car.

Then, they install two batteries-- one for the engine, the other for the cabin controls.

A rocker cover is fastened to the engine to stifle any noise.

They hook up a large air-intake system because optimum engine function requires a lot of airflow.

There will be no fingerprints on this windshield.

After it's wiped clean, workers use a pulley system with suction cups to lower it onto the car.

It's taped into place to allow the adhesive to set, then it's measured to ensure a perfect fit.

Next, the wheel-arch liners are installed.

These hefty guards will protect the car body from mud, gravel, and debris.

Finally, the wheels are mounted, and this rolls-royce is ready to roll.

It takes several weeks to assemble a rolls-royce, compared to the day or two it takes to manufacture an ordinary vehicle.

That's part of the reason why one of these will set you back a princely sum.

But if you win the lottery, this could be one way to splurge.


Binoculars
Sparklers
Rubber Boots
Circular Saw Blades

A pair of binoculars is essentially a handheld double telescope.

Light rays from the object you're viewing enter the lenses on the far end, the objectives.

This projects an image just behind those lenses inside the binoculars' housing.

The smaller eyepiece lenses you peer through then magnify that image.

The objectives are curved, causing the image to appear upside down.

The turn it right side up, each binocular half needs a glass prism.

Using u.v.-light-activated glue, workers mount several prisms on steel plates that take them through a series of grinding and polishing steps.

Protective paint prevents any dust from contaminating the pristine surface.

Grinding with diamond dust removes mere tenths of a millimeter of glass.

Polishing with an even finer abrasive removes another 1/100 of a millimeter.

At the end of it all, the three sides are perfectly flat.

This minimizes reflection, critical for making the glass see-through.

To make each prism, they glue two pieces of glass together at 90 degrees.

This special machine ensures the angle is precise.

A shot of u.v. light dries the glue.

The first piece of glass rotates the inverted image 90 degrees.

The second rotates it another 90 degrees, completing the flip.

Now for the objectives.

These curved lenses have undergone the same grinding and polishing steps as the prisms.

Now they go through a nine-stage computer-guided cleaning process.

After inspecting the lenses, a technician glues two together.

A double lens limits a type of distortion that causes fringes of color to appear around the image.

It's critical to match them to each other perfectly.

If the alignment's off by more than just 1/100th of a millimeter, the image will be poor.

This alignment machine displays a dot representing the center of each lens, so it's just a matter of matching the dots.

A 2-second shot of u.v. light dries the glue.

Next, a technician loads mineral pellets into a vacuum chamber.

Their exact formulation is a company secret.

The pellets produce an anti-reflection lens coating that lets more light come through the lenses.

Inside the vacuum chamber, a beam of electrons evaporates the pellets into microscopic particles that coat the lenses.

It's time to begin assembling the binoculars.

First, the objectives go into the housing, which is usually made of plastic, aluminum, or carbon.

Workers clean the lenses with a few blasts of compressed nitrogen...

Then secure them in place with threaded holding rings.

Now a few drops of glue behind the objectives, where the prisms will go, another blast of nitrogen to remove any dust, then they insert the prisms.

This optical machine aligns the focal points of the prism and its corresponding objective.

Then, some more glue to lock in the positioning and a blast of u.v. light to dry the glue.

Now they silicone the objectives and prisms to the housing's middle section.

Silicone creates an airtight and waterproof seal.

This holding mechanism presses the parts together while workers drive in the screws.

Onto the opposite end of the middle section go the oculars, the smaller lenses through which you look.

Those also attach with threaded holding rings.

Now, through a valve on each side, a machine sucks air from the housing and injects nitrogen gas.

Nitrogen prevents the lenses from fogging up.

A day after filling, they recheck the nitrogen pressure to make sure there's no leak.

This factory puts all the binoculars it produces through rigorous testing, subjecting them to prolonged vibration, water pressure, extreme heat, freezing temperatures, and other trying conditions.

After every test, inspectors make sure everything still works perfectly, both mechanically and optically.

Sparklers have sizzled on the party scene for decades, adding pyrotechnical glitter to weddings and birthday celebrations.

They evolved from more traditional fireworks and are the only kind that the consumer can handle when lit.

Lighting one definitely means excitement is in the air.

The splash of flash can last a minute or more, depending on the length of the sparkler.

They start with steel wires that are about 19 inches long.

They load bundles of them into slots of a sorting machine.

The machine vibrates, and the wires fall in single file into smaller openings.

The operator then moves a spring-loaded wooden rack into position.

It opens like the bellows of an accordion.

The operator rocks the sorting machine overhead, and the wires drop into the slits of the rack, perfectly aligned.

After 300 sparkler wires have fallen into position, the operator pulls a handle to close the rack.

Now, clamped in the accordion-style rack, the wires are ready to move on to the next station.

Wires for parade sparklers are much longer-- 36 inches, in fact-- which means they're heavier than ordinary sparklers.

The operator loads each of these wires manually into a rack that's larger and sturdier than the last one.

This system of loading is a lot more time-consuming, but parade sparklers are worth the extra trouble because they'll have a longer burn time-- up to four minutes.

Next, an operator loads boric acid and barium nitrate into a big mixing tank.

The barium nitrate is an oxidizer and will help the sparkler burn.

The boric acid is a neutralizer.

He adds water and mixes in cornstarch.

It will bind all the ingredients together.

Next, he pours in some very fine iron filings.

These bits of iron will give the sparklers their gold color.

The operator then suits up in protective gear and closes the door.

He's the only one allowed inside to load the sparklers' most volatile ingredient--  aluminum powder.

Once mixed into the wet slurry, the powder is virtually harmless, and they don't need to take as many safety precautions.

Chain conveyors now move the rack of sparkler wires into position.

An elevator lifts up a tank of the sparkler slurry to dip the wires in it.

The next rack of wires then moves forward for dipping.

286 racks of wires move through this dipping station every hour and 45 minutes.

They go through a second dipping station for one more coating.

The two coatings double the diameter of the wires.

After each dip, wires ride an overhead rail through an oven to bake the sparkler slurry until it's hard.

An inspector then examines each sparkler.

She checks for cracks and defects.

Any wire that's flawed will be rejected because these sparklers have to outshine the competition.

It takes her about three minutes to examine the 300 sparklers on a rack.

They check the diameter of each sparkler by sliding it through a template, and they bend it to check its integrity.

The sparklers have been stored for a week prior to packaging to allow them to cure.

And now they're ready for a party, and they're sure to be the center of attention.

Wellington boots, billy boots, galoshes.

By any name, rubber rain boots owe their existence to a 19th-century american, charles goodyear.

He invented the vulcanization process, a way of keeping natural rubber from deteriorating.

Nowadays, rain boots are made from a synthetic material called thermoplastic rubber, or tpr.

They're functional--  even fashionable.

Making rubber boots begins with spools of polyester yarn for their lining.

A colored spool adds a thin line of color to indicate the foot size of the lining.

A computer-programmed machine crochets the yarn with 242 needles.

As we can see in slow motion, each gate opens completely, then closes on the yarn.

The needles rotate 750 times per second.

They can program the machine to make linings for any size of boot.

For quality control, workers spot-check a few linings from every batch.

Now the action moves to this automated injection-molding machine with six stations.

Each one produces a pair of boots.

Workers carefully roll a pair of linings onto each station's foot form, called the last.

These lasts will create the space inside the boot for the lower leg and foot.

A five-part boot mold closes around the foot last.

Then, a high-pressure injection screw pushes in melted synthetic rubber, first in the soles, then in the upper boot.

The company lab regularly tests samples of the synthetic rubber pellets that feed the injection machine to make sure they melt and flow well.

The lab technician pours in some pellets, melts them, then pushes in a piston to extrude the molten rubber.

The machine measures what's called the melt flow index.

Back on the factory floor, a large suction hose feeds rubber pellets to the injectors-- black for the boot body, red for the soles.

And at this factory, nothing goes to waste.

It recycles rubber leftovers or rejects of all colors into a batch of black rubber.

The suction hose then sends the pellets into a hopper which feeds the barrel of the injection unit.

The heater bands inside the barrels melt the pellets at 200 degrees celsius.

Then, at the precise moment the mold arrives, the injector shoots in the molten rubber.

Giant clamps apply pressure for about 10 seconds, then release.

A hydraulic cylinder pushes up the last, helping to extract the boots.

Then it's quickly on with new linings for the next pair.

Total molding time?

Just 30 seconds.

The boots cool for 45 minutes, then head off to packaging...

Making just one stop along the way at the pad printing machine to get the company's logo.

Elsewhere in the factory, a seamstress carefully constructs a patterned boot lining.

The factory crochets white linings in a continuous roll, then has another company print on the design.

The trickiest part is shaping the toe because she has to curve and cut the material at the same time.

For these patterned boots, the machine injects a transparent synthetic rubber into the mold so that the printed lining will show through.

The mirror-finish surface of the mold cavity produces a high-gloss boot.

The printed boot requires more work and costlier materials and is therefore more expensive.

After the molding, for example, it has to go to the trimming station.

There, a worker shaves off excess material from the top of the boot.

Then he sews on a fabric binding to sandwich the lining.

The factory randomly selects a boot from each batch and puts it through a battery of tests on this flex machine.

It bends the boot in various ways some 300,000 times, ensuring that these rain boots can walk the walk.

When a construction site is buzzing with activity, it's usually the sound of the circular saw.

Its spinning teeth can take a bite out of any job in seconds.

There are many claims to the invention of the circular saw, but there's no doubt that when its design was perfected in the last century, it revolutionized woodworking.

With a circular saw, you can give odd jobs a whirl, and when the sawdust settles, you may have discovered your inner handyman.

To make a circular-saw blade, a laser burns into a sheet of steel to cut out jagged disks in the basic shape of a circular-saw blade.

They feed each disk to rollers that press grooves onto both sides.

These grooves are tensioning rings that will keep the blade from vibrating while cutting.

Without these grooves, the circular blade wouldn't cut straight.

At the next station, the assembler measures sags and buckles before feeding the disks to a machine that rolls them flat like a pie crust.

A grinding wheel polishes the blade.

And then they load barrels of the disks into an oven to bake until they're very hard.

This will take about 24 hours.

Meanwhile, carbide tips for the blades' teeth funnel past a laser that confirms they're properly positioned for the next step.

A robot then picks up one tip at a time and delivers it to nozzles.

The nozzles pump a paste called flux onto it.

Another robot places a piece of solder metal on the flux.

The next robot delivers the tips to the saw-blade body.

Elements melt the solder metal and flux to fuse the carbide tips to the teeth.

It's a technique called brazing.

Teeth with carbide tips last longer without losing their sharpness.

Circular blades for sawmills have a larger and different design.

They brush flux around a side hole and then place soldering metal on an elongated carbide tooth.

They braze the tooth to the flux-coated hole and install several more of these carbide side teeth.

The side teeth will enable this sawmill blade to tear through big logs.

The smaller circular-saw blade now spins on an axle while a spray nozzle sandblasts it.

The sandblasting cleans the surface and gives the blade a brushed texture.

A mechanical finger now moves one of the blade's teeth into position for sharpening.

A grinding wheel tapers each tooth.

A different wheel moves in and grinds the outside diameter of the blade.

The geometric angle of the grinding can vary, depending on the type of blade being made.

The grinding wheel then hones the face of each tooth to give it a sharper edge.

Next, a straightening specialist pounds out any remaining bumps in the blade...

And double-checks it with a straightedge tool.

He wipes off any smudges and then holds the blade to the light and examines it to confirm that it has no flaws.

A laser then etches the company insignia onto the blade.

And now the circular-saw blade is ready for its close-up.

A camera focuses on the teeth and sends the picture to a computer.

It analyzes the cutting angle and the clearance of each tooth to make sure each one measures up.

The result is circular-saw blades that should be able to keep their edge on the job.