thread maker tool - Page 1
Forum section: electronics / general

author: akis
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:00:14 pm
content: I would like to drill a hole on a heatsink so as to screw in directly M3 size screws without needing a nut at the other side. These tools are called "machine taps" or something like that, but I have no experience with them. The screws I am using are pretty standard they are listed as "M3 x 0.5mm pitch". I typically use a nut on the opposite end, but in this case I will not have access to the back side so instead of drilling a 3mm hole I need to drill a threaded hole to screw into it directly. Can someone tell me how it is best done?

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 01:09:06 pm
content: 2.5mm hole and use the set of 3 thread cutters - set of 3 to gradually cut the thread - you need to make 1 pass witch each cutter. and don't forget the oil ! you have to lubricate the cutters in order to avoid excessive wear. (ok. aluminium is soft, but anyways...)there are also single pass cutters , but i don't like them - they are introducing much more stress to the material being cut.

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 01:19:59 pm
content: forgot to mention - the oil don't have to be cutting oil (the one used when machining steel), i'm using silicone oil when cutting threads to aluminium, but any oil would do the job for aluminium (except vegetable oils)so basically this is all you need:

author: akis
author_rank: Frequent Contributor
timestamp: June 16, 2014, 01:47:41 pm
content: Damn I just bought on ebay a single 3mm thread cutter, did not see anything in "three parts" ??http://www.ebay.co.uk/itm/331013438009?_trksid=p2059210.m2749.l2649&var=540232986841&ssPageName=STRK%3AMEBIDX%3AITCan I use vaseline or engine oil (synthetic) instead ? I mean we are talking less than a drop of oil right?

author: Stray Electron
author_rank: Super Contributor
timestamp: June 16, 2014, 01:52:39 pm
content: If the heat sink is aluminium, then don't use oil for lubrication. Use kerosene (paraffin to Europeans) or a lubricant that made for especially threading in aluminium. WD-40 also works well in aluminium. DO NOT use a chlorinated solvent! It can react with the aluminium chips and WELD the tap into the hole! Clearance hole is typically 70 to 75% of the major diameter of the thread. Larger percent of thread size will be easier to tap but will take away a portion of the thread and the thread will be slightly weaker so the exact size of the clearance hole is an engineering decision but 70 to 75% is common. But charts giving the exact size to drill for each thread size are PLENTIFUL and easy to find. Look for "tap drill chart". 'Machinery's Handbook' is a great source for information like this! It's updated and republished annually and has been in publication since at least the 1920s. But to continue, if the threaded hole is a thru hole and not a blind hole (a hole that doesn't go through but has a bottom) then you only need a standard "starter" tap to tap it with. OTOH if you're tapping a blind hole AND you need threads that go as close as possible to the bottom of the hole then thread with a starter tap and bottoming tap. Starter taps have a long tapered section which makes it easier to start them in a drilled hole but the bottom of them won't cut the tread to the full depth. A bottoming tap has very little taper so it will cut full depth threads but they're difficult to start in drilled hole, so you use them after tapping with a starter tap. They also make a "plug" tap that is a compromise of the two and has short taper. But as I said before if your hole is a thru hole you can just use a starter tap and go in far enough that it cuts full depth threads all the way thru the material.OH and if you've never used a tap before, the secret to using on is to "clear" them frequently by reversing them and letting them "clear" the chips out of the hole. If you don't then the chips WILL jam the tap and you may not be able to remove it and it will LIKELY break off in the hole! How often they need to be cleared depends on a lot of factors including how deep the hole is, how narrow it is and the precentage of material that was removed with the clearance drill hole. Tapping narrow, deep holes is very difficult and a lot of people break taps off in holes and it's actually a big sideline business in machining to remove broken taps! It's also a LOT easier to avoid jamming taps in the hole can be a thru hole since the chips can fall out of the bottom rather than being jammed between the tap and the worked material. If your work or your part is critical then practice on some scrap before you try to tap your good item.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 16, 2014, 01:56:40 pm
content: Quote from: akis on June 16, 2014, 01:47:41 pmLink showing three types of taps:http://www.kmstools.com/blog/hand-taps-proper-tapping-techniques/Anyoillubricant is better than none! Just don't use anything that's chlorinated!!!

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 02:00:48 pm
content: the single pass tools are working well for threads not being overstressed, and honestly any transistor/IC package have a recommended/maximum tightening torque in the range of 1-2Nm, so no worries.and yes we're talking about such a tiny amount of oilany engine oil (including mineral oils) will work well for small threads like M3. (just avoid the oils used for cooking)

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 02:10:15 pm
content: @ Free Electron :ad WD40 - what is that if not a mixture of oils and other additives ?using oil for small diameters is ok for aluminium (otherwise please explain to all of my heatsinks that they should spit off the power transistors and erode to dust in a instant, and also explain to my threading tools that they have to jump back to the heatsinks and get stuck there)

author: KJDS
author_rank: Super Contributor
timestamp: June 16, 2014, 02:20:40 pm
content: For metric screws the drill diameter for a cut tap, as opposed to a roll tap, is the M number minus the thread pitch.Take a small block of wood and drill a clearance hole through it to keep the tap square as you're using it.putmrpete222 tapinto youtube search and you'll get more advice than you ever need on tapping.

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 02:28:56 pm
content: Quote from: KJDS on June 16, 2014, 02:20:40 pmthe wooden block is a great tip for keeping the tap squarebut it's even more important to drill the hole perfectly square to the surface (drill press is preferable here).

author: tjb1
author_rank: Regular Contributor
timestamp: June 16, 2014, 02:35:19 pm
content: Quote from: rob77 on June 16, 2014, 01:19:59 pmThose 3 taps are the same tap...the different taps are Taper, Plug and Bottoming. In softer materials you could really start with the bottoming and use that only as long as you start it straight. Taper taps just have a much longer lead in to help start the tap parallel to the hole, plug are common as they are a compromise of both.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 16, 2014, 02:43:27 pm
content: Quote from: rob77 on June 16, 2014, 02:10:15 pmWD40 is mostly kerosene. (And kerosene is an oil but a light oil unlike most thread cutting oils) Along with additives such as drying agents. But I've already said that it can be used when drilling and taping aluminium. In fact, it works rather well for that! Most oils, particurally threading oils, are too thick and heavy and won't flush aluminium chips out of the hole very well. Also the sulfur in regular cutting oil can react with aluminium and discolor it. For aluminium, I use water soluable oil (fish oil) that's made for machine work. But I don't suppose that the OP wants to have to buy a 5 gallon container of that!OP be generous with the oil, one of it's main jobs is to wash the chips out of the hole and off of the tap. Besides lubrication, it also cools the tap and work piece.Rob: If your transistors are jumping off of their heat sinks perhaps your threads aren't what they should be!

author: ion
author_rank: Regular Contributor
timestamp: June 16, 2014, 02:49:25 pm
content: Quote from: rob77 on June 16, 2014, 02:00:48 pmWould be interested to know why. I've used it to drill aluminium and it works well enough in a pinch.

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 02:58:23 pm
content: Quote from: ion on June 16, 2014, 02:49:25 pmi have a bad experience with a vegetable cooking oil - once my taping tool got stuck (haven't had other oil handy) but i was able to release it without any damage by heating the aluminium .

author: Lightages
author_rank: Unknown
timestamp: June 16, 2014, 03:02:47 pm
content: Almost any type of oil will work. Just make sure you practice on a piece of aluminum you don't care about first. You just can't drill a hole and start screwing the tap into the hole. There is some technique and feel required to get good threads and not break a tap. Be prepared to buy more than one set of taps as 3mm are easy to break.

author: ajb
author_rank: Super Contributor
timestamp: June 16, 2014, 03:27:12 pm
content: It's also helpful to use a countersink bit to put a slight chamfer on the entry hole before tapping. Makes it easier to get the tap started, and reduces or prevents a bur from forming on the edge of the hole.

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2014, 03:31:02 pm
content: With soft materials like aluminium you can also use a non cutting tap, called a roll or polygon tap, which makes the thread by deforming the material into the thread form without cutting chips. Makes for a stronger thread in the hole, but generally requires a larger drill size, and definitely needs a thread lubricant. If you are going to buy taps buy spiral taps, as they are stronger in smaller sizes, and cut better.

author: kripton2035
author_rank: Super Contributor
timestamp: June 16, 2014, 03:36:55 pm
content: with aluminium, I directly screw the 3 mm screw into a 2.5mm holeno need for one or even 3 taps or oil !!!not the same in steel thought...

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 03:43:28 pm
content: Quote from: kripton2035 on June 16, 2014, 03:36:55 pmare you the Superman or Chuck Norris in person ?

author: kripton2035
author_rank: Super Contributor
timestamp: June 16, 2014, 04:05:01 pm
content: Quote from: rob77 on June 16, 2014, 03:43:28 pmnot at all. but just try it. if there is a hole of 2.5mm the screw itself is enought to make the path insidereally no need for a tap. in aluminium (or wood also) but not in steel

author: SeanB
author_rank: Super Contributor
timestamp: June 16, 2014, 04:09:21 pm
content: If you are reusing PC mounting screws those are often trilobular self forming screws, which will form a thread into soft materials like aluminium and thin steel plate. No thread forming needed, just a nut driver to prevent stripping the head.

author: robrenz
author_rank: Super Contributor
timestamp: June 16, 2014, 05:01:38 pm
content: I thought this was about a tool to start forum threads so I didn't even look until now

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 05:03:32 pm
content: Quote from: kripton2035 on June 16, 2014, 04:05:01 pmwood works for sure, i'm doing that myself as wellbut the aluminium... i'll give it a try ..... but a regular M3 screw is definitely not hard enough to do that sort of thing... are you sure you are not using self taping M3 screws ?

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 05:18:23 pm
content: Quote from: tjb1 on June 16, 2014, 02:35:19 pmthose 3 taps are definitely NOT THE SAME TAP ! those are for progressive taping - you go with the "single strip first", then "double strip" and then the "no strip" each one is cutting he groove deeper and deeper. - to cut precise thread you have to do it progressively.

author: KJDS
author_rank: Super Contributor
timestamp: June 16, 2014, 05:31:09 pm
content: I used to design big combline filters, typically held together with 100+ M3 screws, and we'd make 25000 a year of a design. I know a few things about screwingYou can force a standard A4 grade stainless screw into aluminium, but unless you drill the hole at 2.75 instead of the 2.7mm that you'd use for a roll tap then there's a significant risk it will snap the screw. By significant I mean more than 1%, which doesn't sound much, but when you're putting in 2.5million screws a year us a lot of rework. And with the hole drilled at 2.75mm you lose a lot of strength, risking stripping the thread when you tighten it.You can use trilobal threadforming screws, These are more expensive then normal screws but the snap rate is about 0.2%. That is low enough to not worry the hobbyist, but would still have left 5000 items of rework a year on a single product.Unless you need the thread going to the bottom of the hole, then a single tap is fine. There only needs to be 3mm of good thread to hold an M3 screw, if you can drill deep enough so that the lead of the tap is beyond the depth of the screw then it's pointless faffing about with three separate taps.The other useful trick we used was to counterbore each hole, just about 2.5mm diameter for 1mm depth, so that any burr raised when tapping or extracting the screw would sit in the counterbore and not hold the lid off the mating surface. We'd use custom form drills for this.

author: tjb1
author_rank: Regular Contributor
timestamp: June 16, 2014, 06:20:15 pm
content: Quote from: rob77 on June 16, 2014, 05:18:23 pmUh no, those stripes identify the tap and you do not have to use all 3 to do a thread. Single is suppose to be TAPER tap, Double is PLUG tap, None is BOTTOMING. Really has nothing to do with the thread itself, you will have a hard time aligning a BOTTOMING tap in a plain hole to start it. That is what the TAPER tap is for, it has a very long taper at the front to allow it to guide itself into the hole. This TAPER tap is fine for almost all situations, the only time you move to the other taps if you want to cut FULL threads to the bottom of a blind hole. In fact, TAPER isn't that common since a PLUG can really do the same thing.Did you buy your taps from China? Every tap looks exactly the same, the taper on all of them appears the same and the last tap with no stripe on it is certainly not a BOTTOMING tap because it has a point on it.Look at the picture

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 06:31:58 pm
content: Quote from: tjb1 on June 16, 2014, 06:20:15 pmfirst look at the post you commented on pleaseyou commented on my very own post with my very own picture taken few minutes before i made the post - showing my very own set of taps which i use to tap threads into heatsinks. and i'm competent enough to know what i'm usinghere's the picture again:

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 06:42:31 pm
content: Quote from: tjb1 on June 16, 2014, 06:20:15 pmeven your picture is showing the same as i mentioned - note the progressing sharpens of the cutting edges from left to right and the increasing depth of the groove - so it's a set of 3 taps for progressive taping. (1 strip, 2strips, finish with no strip) - but those are the ones for taping blind holesi never said my taps are bottoming - mine are through hole.=== edit - forgot to comment on chinano, i'm not buying machining tools from China . i'm buying those (taps, drill bits, milling bits, cutting disks) in local hardware stores , because those machining tools from china are just toys

author: Monkeh
author_rank: Super Contributor
timestamp: June 16, 2014, 07:15:52 pm
content: 'progressive tapping' is an exercise in time wasting for normal applications.For simply putting an M3 thread in a piece of aluminium, or even mild steel, to hold the minimal torque required for mounting components or covers, a plug tap is the only tap you need. That is the middle one, if you've missed that point.

author: tjb1
author_rank: Regular Contributor
timestamp: June 16, 2014, 07:24:35 pm
content: Quote from: rob77 on June 16, 2014, 06:42:31 pmThose stripes indicate type of tap...TAPER, PLUG or BOTTOMING. What I said was that ALL 3 of your taps look exactly the same from the tip to the taper. None of the tapers appear to change. Those stripes have nothing to do with the H limit or class of fit. You are just wasting your time running all 3 taps through and in a blind hole they will do no different unless they do in fact have a differing tip taper between the 3 which it appears they do not.Even though the cutting tip is different, you can tap a hole fine with a PLUG tap and run a bolt into it. Bolts are generally not a sharp point thread either.

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 07:36:42 pm
content: Quote from: Monkeh on June 16, 2014, 07:15:52 pmlet me disagree - either you use all 3 of them or you have to use a different single-pass tap (which is more like the last one - without strips) . otherwise your threads will be out of spec (if talking about correct taping/cutting thread)if you want just screw it "somehow" together - then as others suggested - just skip the taping(gave it a shot in the meantime... well... i'm not impressedthread on the screw flattened, but there are some kind of a grooves in the hole... it was a exercise to screw it in... it withstands a little bit of force... but i wouldn't recommend that )using just the middle tap only is something in between - but it's better than not taping at all. i will rather keep spending the extra 1 minute to tap it correctly - use all 3 in the set

author: Monkeh
author_rank: Super Contributor
timestamp: June 16, 2014, 07:38:59 pm
content: Quote from: rob77 on June 16, 2014, 07:36:42 pmYour taps are odd, sorry to say. Normal plug taps will fully form the thread, only the first few turns are tapered down.

author: KJDS
author_rank: Super Contributor
timestamp: June 16, 2014, 07:50:53 pm
content: Quote from: Monkeh on June 16, 2014, 07:38:59 pmAs someone who had design authority on about 125 million tapped M3 holes a year into aluminium for five years, I can safely say that not one of those had more than one tap inserted. There's no need to use three taps unless you need the screw to get to the bottom of the hole, and even then I'd usually insist that a design was changed so that wasn't necessary.

author: rob77
author_rank: Super Contributor
timestamp: June 16, 2014, 07:51:33 pm
content: Quote from: tjb1 on June 16, 2014, 07:24:35 pmonce again and slowly.... I'm using those to cut threads - each pass is CUTTING DEEPER INTO THE WALLS OF THE HOLE and is producing chips ....if you think the TIP of the taping tool has anything to do with the thread cutting/taping process then you're wrong. the tip of the tool got one job - center the tool in the hole at the beginning. the shape of the tip has nothing to do with the cutting edges of the tool.and by the way... you have to be the Superman in person , because otherwise how on earth would you be able to see such a details on a 1024x768 picture ? the thread groove depth for M3 is approx 0.25 mm - the difference between the cutters is in the 0.05 - 0.1mm range.... man if you are not the Superman in person then you must have the NCIS , CSI enhance, uncrop, turbo zoom image processor to see that on 1024x768

author: Monkeh
author_rank: Super Contributor
timestamp: June 16, 2014, 07:54:50 pm
content: Quote from: rob77 on June 16, 2014, 07:51:33 pmThat's what a taper is for.Yeesh.QuoteTaper.

author: deth502
author_rank: Frequent Contributor
timestamp: June 16, 2014, 09:04:17 pm
content: i gotta jump on the pile up on rob77.i dont know much about electronics, but ive been a machinist for YEARS, and ive NEVER heard of anything like hes saying.and rob, to comment on your comment about being able to tap a hole "in spec", saying that by itself means absolutely nothing. there are hundreds of "standard fits" for calling out a spec, and non of them need to be used in a print. whatever the tolerances called for in the print are the "spec" on each job. to say just randomly say something is "in spec without a detailed explanation of what "spec" you are working to is meaningless.and to the op: lots of back and forth and technical talk about taps, if you dont know anything about them, im sure this may be very confusing for you, ever thought of just using a few self tappers? from reading your post i get the idea that this is a "one-off" type of project. is a fancy tapped hole really worth all of this to you?

author: tautech
author_rank: Super Contributor
timestamp: June 16, 2014, 09:29:38 pm
content: 35 Years ago when I did light engineering, taps came in Taper, Intermediate and Plug.There was never any confusion of their names in this way.They were and still are available singularly or as a set of 3.If I need to buy one today, I just get an intermediate.A drill tapping chart is indispensable.In the small sizes that we mostly use in electronics, attention to detail is the key or you will snap the little blighters. Practice on thin materials and the go thicker as confidence grows. Be careful with anything more than 3 mm thick to start with.When you have broken a few then you have thefeelfor tapping.We tapped Plastics, Ali, Cast Ali, Mag Ali, Brass, Cast Iron, Cast steel, Mild steel and high tensile steels.Magnesium Ali, Brass, Cast Iron were the easiest.Ali and HT steels could be tricky, HT steels just tough, Ali if your taps were a little dull would gall(pick up).Often for less used sizes we only had intermediates and mostly the holes weren't blind so you could run the tap as deep as was needed.If your tap was still sharp and not in a blind hole, you could run it as far as needed in one continuous motion, but not in all materials.Every material is different, some require a cutting fluid, most do not if care is taken.

author: ecat
author_rank: Frequent Contributor
timestamp: June 16, 2014, 10:33:47 pm
content: Quote from: KJDS on June 16, 2014, 02:20:40 pmSome good advice in this thread but this is the best I've read. Let me do it for you:That is part #1 of his series of Machine Shop Tips, do yourself a favour and watch at least the next 10

author: Paul Moir
author_rank: Frequent Contributor
timestamp: June 17, 2014, 12:23:46 am
content: Those serial taps are not very common in North America. My handy catalogue has 25 pages of various styles of taps but not one set of serial taps. I've been meaning to get a set because I do a lot of hand tapping stainless and I thought they'd help, but finding them in inch sizes is very difficult. Switching between the (very commonly available) taper, plug and bottoming helps but really less total cutting per tap would be less torque.I think the tool manufacturer's focus their technology more on automated tools, and so taps geared for that work better. Those guys will never do it in multiple steps if at all possible because they loath tool changes. But all this is immaterial when tapping Al since it can easily be done in one pass with a traditional hand tap.One caveat: I've run across heat sinks that use super gummy aluminium which is a real pain to cut. I suspect it might be unalloyed. If you get into trouble don't keep going. Just carefully work the tap out and clean out the chips.

author: ovnr
author_rank: Frequent Contributor
timestamp: June 17, 2014, 12:54:51 am
content: +1 for just running a plain M3 screw into your drilled 2.7mm hole. I've done it countless times, and as long as you use some lubrication it's fine. Just be sure to start it straight and for the love of all that goes "bang" when you reverse it: Do not use a power tool. Seriously.Of course, using a proper tap gives you a nicer finish and less risk of things going pear-shaped (... but I think I've actually broken more M3 taps than when using screws to tap the hole). Just get some spare bits and see how you get on with it.And no, seriously, you do not need to use multiple taps.

author: GeoffS
author_rank: Unknown
timestamp: June 17, 2014, 01:05:15 am
content: Single taps are all that's needed for this application.Be sure that the tap is at 90 degrees to the work, this will help prevent tap breakages, as will suitable lubrication and backing the tap off regularly to dislodge swarf.To help with keeping the tap vertical, drill a hole, that just allows the tap clearance, in a 1" block of wood and use it as a guide.

author: Lightages
author_rank: Unknown
timestamp: June 17, 2014, 04:39:24 am
content: Quote from: Paul Moir on June 17, 2014, 12:23:46 amActually you do not want to work stainless too much. It work hardens very quickly. You generally need to make your full thread in one pass. The next pass the surface will have work hardened and you are almost guaranteed to break the tap. So tapping in stages is not a good idea for stainless.

author: johansen
author_rank: Super Contributor
timestamp: June 17, 2014, 04:54:25 am
content: motor oil is fine, but your experience will depend on the aluminum.pure aluminum is like lead, so your heatsinks have silicon and iron added. iron because they probably threw a bunch of scrap in the pot which had iron in it.so, you can get away with no grease because the aluminum won't stick to itself. but, most likely it will just a bit.. a 3mm tap is hard to break off provided you drill an oversized hole which is most likely the case if the bit is dull and it drills a triangular shaped hole. so start it straight and you'll soon get the feel what "cutting threads" feels like.. as opposed to what "smearing aluminum threads off" feels like.you might be able to get away with a 3/32 drill bit.

author: Richard Head
author_rank: Frequent Contributor
timestamp: June 17, 2014, 10:15:40 am
content: I have found that an electric cordless drill is excellent for tapping holes. The forward/reverse feature allows one to advance and withdraw the tap very easily. Also, the torque limit can be set to reduce the chance of breaking the tap. It's much easier than using a tap wrench, in my opinion.

author: akis
author_rank: Frequent Contributor
timestamp: June 17, 2014, 10:46:33 am
content: An unbelievable amount of detail for what I had thought was a simple question. So I deduce that:1) aluminium is soft enough to force a M3 screw into a 2.7mm hole without prior tapping. Noone has mentioned the thickness of the aluminium here, I presume this holds true for a 1.2mm of aluminium but maybe not so true for drilling into a solid heatsink with thickness of 5mm or more? Anyway I do not think I want to try it.2) Drill a 2.5mm hole, countersink the top a little bit, then use the hand tool. the intermediate one to slowly cut the threads using some lubrication in the process. If it gets too tough reverse out to remove debris and try again.3) three general types of tap bits, for starting, continuing and finishing (bottoming) a (blind) hole. For a through hole the intermediate is just fine.4) Chinese tools are generally badly made, and I bought this one in the picture - Not sure if this is starting, intermediate or bottoming.5) How on earth do you drill a perfect 2.5 mm hole? I have a drill press, but am not sure it will cut a good hole, I mean the drill bit has to be perfect, the drill chuck perfectly balanced we are talking Rolls Royce engine quality needed here else it will be a triangular and larger than needed hole, am I right?

author: Monkeh
author_rank: Super Contributor
timestamp: June 17, 2014, 10:49:37 am
content: Quote from: akis on June 17, 2014, 10:46:33 amBack it up half a turn every turn to turn and a half to break the chips. If you keep going until it starts to jam you'll have a bad day.QuoteThis is a plug tap, and will be perfectly adequate for soft aluminium. It appears to be a 'gun' tap, so don't use it in a blind hole.QuoteA perfect hole? With tools which cost more than your house.A hole suitable for fixing a component onto a heatsink? Your drill press will be fine.

author: Kjelt
author_rank: Super Contributor
timestamp: June 17, 2014, 11:11:29 am
content: Perhaps Europe differs from the US but I must agree with Rob77 on his statements on his three part tap set.They are formanual tappingonly (not machine tapping where you have a single tap) and fordifficult tough material(think steel not alu which is soft).Now you can argue all you want but have a look at this set for instance which in dutch clearly states "first, middle and last tick" which is exactly how you should use them in tough material, because if you wanted to do it with a one tap turn only it would break or you had to drill the hole larger then ideally so it will not fit as good as should. Have a good look at their start shape, they all are definitely not for bottoming.http://www.tools2go.nl/9157016/3-delig-m3-x-0-5-tap-set?gclid=CPyPq_jhgL8CFaQIwwod62IA_QThat said, for aluminium you can just use a machine tap or one time tap, no problemo.

author: KJDS
author_rank: Super Contributor
timestamp: June 17, 2014, 11:42:02 am
content: It's unlikely to matter if you're just screwing a transistor to a heatsink if the hole is a little oversize. Unless you need to tighten teh screws up too their maximum otrgque on minimal thread depth then using a cut tap in a 2.6mm hole won't make much difference.

author: rob77
author_rank: Super Contributor
timestamp: June 17, 2014, 11:43:00 am
content: Quote from: akis on June 17, 2014, 10:46:33 am1. don't do that - you will be not able to say if the 1-2 Nm torque is coming from the friction of the screw or from tightening the packege to the heatsing , so you might end up with poor thermal junction. i gave it try yesterday and it's nothing you would like to use in any of your projectsprobably works better with pure aluminium but with the alloys i have it's not usable (ok. it holds the screw in place to some extent, but i don't recommend it).2. half turn back every 1-2 turn for small diameters and softer metals, for larger diameters half turn back every single turn.3. that tool is a single pass - and looks good - at least it's hardened according to the different color.4. a decent drill press shouldn't have more than 0,05mm eccentricity so no problem. if your drill press has more, then a good trick is to use smaller drill bit - e.g. 2,4mm one to get a 2,5mm hole

author: Monkeh
author_rank: Super Contributor
timestamp: June 17, 2014, 11:47:54 am
content: Quote from: Kjelt on June 17, 2014, 11:11:29 amAnd taper, plug, and bottoming taps are commonly refirst to as first, second, and last taps. I think you'll find all three of those are exactly the same past the first ten threads at most.

author: rob77
author_rank: Super Contributor
timestamp: June 17, 2014, 12:06:06 pm
content: Quote from: Monkeh on June 17, 2014, 11:47:54 ammy last comment on this... HERE IN EUROPE we have a set of 3 tools for manual taping. each of the FREAKING TOOLS HAS A DIFFERENT DIAMETER AND DIFFERENT SHAPE OF THE CUTTING GROOVE ! each tool is cutting deeper into the walls of the hole as the previous one. end of the discussion.either accept it or not, i don't give a rat's ass anymore.

author: sync
author_rank: Frequent Contributor
timestamp: June 17, 2014, 12:21:01 pm
content: Quote from: rob77 on June 17, 2014, 12:06:06 pmExactly. Look at the graphic. The first tap only cuts about 55% of the thread. The middle 80%. So you have to use always the final one.

author: Kjelt
author_rank: Super Contributor
timestamp: June 17, 2014, 12:21:48 pm
content: Quote from: Monkeh on June 17, 2014, 11:47:54 amYes I know what a bottoming tap is, it is used for a hole that is not all the way through and you want the tap to go as deep as possible. Therefore the underside of a bottoming tap is pretty flat. Can you see a flat bottom on the taps in my link? No you can't because they are NOT bottoming taps period.Look at the shapes for pete sake!And as Rob says over and over again and I second , these taps each cut a tiny bit deeper in the side of the material and the tap is only complete after the last (third) tap has been used.And another thing look at the rings, why do you think these sets have ring markings on them? Because you can not easily see the difference between the three. With you tapering and bottom taps the difference is pretty obvious so you don't need any marking.

author: Andy Watson
author_rank: Super Contributor
timestamp: June 17, 2014, 12:54:54 pm
content: Quote from: akis on June 17, 2014, 10:46:33 amIf you want to be a bodgerQuoteI think it's already been mention but it's best to pre-empt the "getting too tough" bit by cutting for say a half-turn, then reverse for a half turn to break the chips. If you get to the stage where the chip has taken up all the space in the flute it's already too late, you will struggle to get the tap in or out.QuoteSee 4 - buy decent drill bits.

author: Monkeh
author_rank: Super Contributor
timestamp: June 17, 2014, 01:17:26 pm
content: Quote from: rob77 on June 17, 2014, 12:06:06 pmBy Europe's definition, I'm in Europe. And those taps are not commonly availableor used, because they're a thorough waste of time in normal materials. You have slightly odd taps, and nobody else uses them for normal work.Please try and give relevant advice and not get so pissed off when people point out that reality is different. You're like a yank with their stubborn insistence on imperial measurements..

author: ElektroQuark
author_rank: Unknown
timestamp: June 17, 2014, 01:35:29 pm
content: I'm in Europe too (Spain). Here we use the same tools as rob77 says.

author: deth502
author_rank: Frequent Contributor
timestamp: June 17, 2014, 09:19:24 pm
content: Quote from: Kjelt on June 17, 2014, 11:11:29 amwell, ill concede. all 3 of those sure do seem to be the same taper. i have never seen anything like that in the us. ive seen undrsize taps for tighter tolerances, oversized taps for the opposite reason, and many, many different styles of specialty taps, but never ones that opened a thread up in steps that needed to be used in order.

author: akis
author_rank: Frequent Contributor
timestamp: June 17, 2014, 10:06:54 pm
content: Quote from: sync on June 17, 2014, 12:21:01 pmNow, wait a minute. I only bought one tool. Which is it? Noone here mentioned that 3 passes are needed to create the correct depth and shape of thread. Doh!

author: rob77
author_rank: Super Contributor
timestamp: June 18, 2014, 01:04:06 am
content: Quote from: akis on June 17, 2014, 10:06:54 pmyour tool is a single pass tool - cutting 100% at once.

author: rob77
author_rank: Super Contributor
timestamp: June 18, 2014, 01:16:57 am
content: Quote from: deth502 on June 17, 2014, 09:19:24 pmthose are pretty common in europe ( ok some UK guys are not aware of them as well)you introduce less stress to the material while cutting the thread, your manually tapped thread is more precise and last but not least - it's less effort to cut in 3 steps than cutting 100% of the thread at once (it's a killer feature for larger diameters and tough materials).

author: mrflibble
author_rank: Super Contributor
timestamp: June 18, 2014, 01:18:32 am
content: Quote from: rob77 on June 17, 2014, 12:06:06 pmWithout getting into the discussion of what should and should not be ... I have a set for hand tapping exactly as rob77 describes. And it works very well thank you very much.What I like about the progressively deeper cuts ... even a n00b like me manages to tap without breaking anything.That and, the resulting thread is actually pretty good. So works for me.

author: WarSim
author_rank: Frequent Contributor
timestamp: June 18, 2014, 02:37:38 am
content: Quote from: rob77 on June 18, 2014, 01:16:57 amWhen reading you first post I recognized what you explained but had difficulty remembering where I ran into it. Looking up the information for confirmation was leading nowhere.I finally figured out where I saw them. When a group of British people can here to Canada for equipment support they used a three pass tap set. It was for a M16 hole onto hardened steal.That was the only time I ever saw a 3 pass tap set. I just assume it was because it was hardened steel and the cut face was too large for a single pass. I never knew that they make 3 pass taps with such small cutting surfaces. Interesting. Since then I have never seen a multi pass tap set. Looks like they are uncommon in North America.On the other hand I have seen a few large multi pass bar stock press dies since. So they must be here on this side of the world for some reasonsThanks for sharingSent from my iPad using Tapatalk

author: sleemanj
author_rank: Super Contributor
timestamp: June 18, 2014, 02:50:27 am
content: You guys are buying single tap sizes for doing a couple of holes, in aluminium, for hobby purposes?Sheesh. Walk down to your local hardware store, pick up a cheap tap and die set.

author: rob77
author_rank: Super Contributor
timestamp: June 18, 2014, 03:11:51 am
content: Quote from: sleemanj on June 18, 2014, 02:50:27 amactually, i got a set of taps - even including the matching drill bitsbut i simply don't like the single pass taps - better results and less effort with the 3 pass ones. i bought that set some time ago, just to have other sizes handy (usually i need only M3 and M4 - so i got a 3 pass sets for those)

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2014, 04:44:24 am
content: Hand tapping a 3 part set works well in most common materials. If you are doing work hardening material like 316l stainless then you go and buy a proper tap and use a power tapping driver with the right lubricant and lube feed to do your hole in a single pass. I have a few taps that are used in assorted applications, the worst is into cast iron, where you have very hard inclusions. Worst metal is an incolel allot casting, which is so hard that you do not tap it, just either spark erode a hole or use a surface milling machine to finish a surface.If you break a tap in a blind hole often the only way to get it out is to spark erode it out with a copper rod and a good flow of coolant.

author: akis
author_rank: Frequent Contributor
timestamp: June 18, 2014, 08:16:06 am
content: You mean copper melts at higher degrees than almost any iron so you melt the iron using copper as the heat conduit? This is how they make anti-tank missiles.

author: G7PSK
author_rank: Super Contributor
timestamp: June 18, 2014, 08:42:41 am
content: For tapping holes in thin sheet or sections you only need a taper tap second taps and plug taps are only required for blind holes. Taps used in machines like laths etc usually have a reversed twist in them like a drill bit but the opposite direction in order to clear chips, You can use these by hands but they are harder to start which is where the taper on the first part of a taper tap comes in.

author: neslekkim
author_rank: Super Contributor
timestamp: June 18, 2014, 12:32:46 pm
content: Quote from: rob77 on June 17, 2014, 11:43:00 amWhat is the correct drillsizes for the various holes?, I'm looking for an tapset for m3, but there are mentioned 2.5mm and 2.7mm here?Found this seller that have various taps etc for decent prices as compared to what I have found here in Norwayhttp://www.ebay.co.uk/sch/ukdrills/m.htmlIn normal shops here I only find the one pass tools, not three pass ones, which I think maybe would be easier to use also?

author: KJDS
author_rank: Super Contributor
timestamp: June 18, 2014, 12:37:05 pm
content: Quote from: neslekkim on June 18, 2014, 12:32:46 pmFor an M3 cut tap then use a 2.5mm hole. For a roll tap use 2.7mm I've put up a picture of a roll tap below, it looks more like a screw and jsut rolls the thread into the material. They aren't generally recommended.http://t1.gstatic.com/images?q=tbn:ANd9GcRXyph36RAp2mnCgatA_lCaNCUwY1x93cwfcBjVODgrcJewGULBMg

author: neslekkim
author_rank: Super Contributor
timestamp: June 18, 2014, 12:54:54 pm
content: Quote from: KJDS on June 18, 2014, 12:37:05 pmcut tap, roll tap?,hm.. This is cut?http://www.ebay.co.uk/itm/350859782830

author: kripton2035
author_rank: Super Contributor
timestamp: June 18, 2014, 03:18:03 pm
content: M3 | PITCH - 0.5MM | DRILL 2.5MM M3.5 | PITCH - 0.6MM | DRILL 2.9MMM4 | PITCH - 0.7MM | DRILL 3.3MM M5 | PITCH - 0.8MM | DRILL 4.2MMM6 | PITCH - 1.0MM | DRILL 5.0MM M7 | PITCH - 1.0MM | DRILL 6.0MMM8 | PITCH - 1.25MM | DRILL 6.8MM M10 | PITCH - 1.5MM | DRILL 8.5MMM12 | PITCH - 1.75MM | DRILL 10.2MM M14 | PITCH - 2.0MM | DRILL 12.0MMM16 | PITCH - 2.0MM | DRILL 14.0MM M18 | PITCH - 2.5MM | DRILL 15.5MMM20 | PITCH - 2.5MM | DRILL 17.5MM M22 | PITCH - 2.5MM | DRILL 19.5MMM24 | PITCH - 3.0MM | DRILL 21.5MM

author: KJDS
author_rank: Super Contributor
timestamp: June 18, 2014, 05:53:07 pm
content: Quote from: neslekkim on June 18, 2014, 12:54:54 pmThat is a cut tap.

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2014, 06:11:00 pm
content: Quote from: akis on June 18, 2014, 08:16:06 amSpark erosion, using an electric arc through an insulating oil. It preferentially erodes the one electrode, allowing you to machine any hard conductive material using a very soft easy to machine mandrel.http://en.wikipedia.org/wiki/Electrical_discharge_machiningFor a little info

author: Monkeh
author_rank: Super Contributor
timestamp: June 18, 2014, 07:43:26 pm
content: Quote from: kripton2035 on June 18, 2014, 03:18:03 pmFixed that for you. Jeez.

author: neslekkim
author_rank: Super Contributor
timestamp: June 19, 2014, 05:34:08 am
content: Quote from: kripton2035 on June 18, 2014, 03:18:03 pmai, damn..that was too easy to find now

author: VK5RC
author_rank: Unknown
timestamp: June 20, 2014, 02:31:02 am
content: Most commonly available taps are just the 3 types of taper, bottoming etc, there are large numbers of other variants (partial, full, overfull). There are some good machining texts that cover these issues over MANY chapters.For small threads (less than 8mmm) it usually makes little difference. You can spend a huge amount of time looking at all the options,....... if the screw fits.......... :-)

author: jetwolfk2
author_rank: Contributor
timestamp: June 22, 2014, 05:42:25 pm
content: i use these often and its simple drill the pilot hole and then a bigger bit closest to the bolt size then use the threader, this way the threader does not get worn as much

author: kripton2035
author_rank: Super Contributor
timestamp: June 22, 2014, 07:07:36 pm
content: Quote from: jetwolfk2 on June 22, 2014, 05:42:25 pmyes but then the thread will not be as deep as it could be ?

author: mzzj
author_rank: Super Contributor
timestamp: June 23, 2014, 06:54:16 am
content: Quote from: sleemanj on June 18, 2014, 02:50:27 amPretty often those cheap tap and die sets are so nasty quality that you will soon regret trying to tap even couple of M3 holes in aluminium.Soft gummy sort of aluminium requires sharp taps with good surface finish if you dont want broken taps and ugly threads.

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 08:21:53 am
content: I bought this one on amazon.fr (build in germany)very good quality and 3 tap sets for less than 25 euros

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 08:24:18 am
content: Quote from: kripton2035 on June 23, 2014, 08:21:53 amWow the french buying german stuff, europe becomes a success and the world is changing

author: cs.dk
author_rank: Unknown
timestamp: June 23, 2014, 08:24:43 am
content: Quote from: kripton2035 on June 22, 2014, 07:07:36 pmThats usually not a problem. A day at work someone slept and drilled 7,5 mm (instead of 6,8 mm) hole to a M8 thread. Just as a test we tried to mount a M8 bolt (8.8), it was almost impossible to turn over. Try make the test your self, you will be surprised over the strength.

author: rob77
author_rank: Super Contributor
timestamp: June 23, 2014, 09:31:17 am
content: Quote from: cs.dk on June 23, 2014, 08:24:43 amthe strength will something like half or less compared to the specs

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 09:33:25 am
content: Maybe in 70 of the 100 cases it is no problem. When you mount unmount the bolt 50 times in that thread and put a lot of pressure on it , it might become a problem in the long run. Let's say it like this, I would not want to ride a rollercoaster ride where all the taps were not in spec.

author: akis
author_rank: Frequent Contributor
timestamp: June 23, 2014, 09:35:56 am
content: Quote from: Kjelt on June 23, 2014, 08:24:18 amGermany must be the only country in Europe where you walk into the supermarket and everything you see on the shelves is ... made in Germany. Italy must be a clilose second, and did not try Austria. But try the same at an English supermarket, everything is made in China. Everything in our kitchen, except our very, very old (and very good) pots and pans (made in Belgium), is made in China, glasses, plates, cutlery (except some specially bought Sabatier knives). I'd say 85-95% of all the kitchen items, and items all around the house, it's all made in China.So there are a few things of note here:1) England does not make anything (tangible) - it is a miracle that the world pays England for anything - the English literally must be selling hot air to the rest of the world and the world is falling for it2) Germany makes everything - they are almost self sufficient3) Italy also makes their own stuff (but it was about 10 years ago when I looked)4) England does not buy from Europe - except some dubious quality food produce, like olive oil, labelled as "made in EU" which in my books means "chinese engine oil, made to look like olive oil, arrived in some weird EU country under different designation and label, repackaged in some weird EU warehouse and lost its "China" stamp, and now sells as genuine EU olive oil. Yes, because as we all know the whole of f*cking Europe is packed with olive trees. Yeah, right....

author: cs.dk
author_rank: Unknown
timestamp: June 23, 2014, 09:37:13 am
content: Quote from: rob77 on June 23, 2014, 09:31:17 amOf course it will be less strong - But it is remarkable, how much torque you can put into it. Maybe i'll make a test later on the day with a torque wrench.But for a heatsink, really this is no problem.

author: rob77
author_rank: Super Contributor
timestamp: June 23, 2014, 09:44:39 am
content: Quote from: cs.dk on June 23, 2014, 09:37:13 amor with a press with a pressure gauge - make one correct in-spec thread and one with larger hole and the middle tap only , put a longer longer in both (kep few mm gap between the bolt's head and the surface of the plate with a taped hole) and try to press the screw in with a press. the one in spec will tolerate more pressure till the threads are ripped of and the joint will fail.

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 10:08:18 am
content: Quote from: Kjelt on June 23, 2014, 08:24:18 amI almost have no french tools in my lab/shop...I buy in germany when I want quality toolsI buy in uk when I dont want to wait for a month for a finaly chinese toolI buy in china when I can wait for itI used to buy in usa but now customs and shipping have become far too expensive from there.german people buy in germany from german shops that have german tools insideuk people buy in uk from uk shops that have chinese tools insidefrench people have almost no valuable shop in france (all shops have moved elsewhere cheaper in europe !)sorry but most of the valuable french manufacturers have gone

author: neslekkim
author_rank: Super Contributor
timestamp: June 23, 2014, 10:56:08 am
content: Quote from: kripton2035 on June 23, 2014, 08:21:53 amThat looked like an good kit, do you have link or name of this? (Havent found the german name for these things yet)

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 11:11:00 am
content: here.http://www.amazon.fr/gp/product/B000K2TC7K/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1but I'm not sure you can see it outer from france ?it is a "Mannesmann 53250"

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 11:41:04 am
content: @Krypton2035 it was a joke, I come to your lovely country a lot of summers since the mid 70's and adore France, but the people were always very protective of mind in a way that, if its origin was not French it was not ok, this was for cars, wine, food etc. With wine and food btw I still agree

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 11:50:11 am
content: Quote from: Kjelt onTodayat 22:41:04for wine and food I also buy exclusively from france !no offense !but my car is a german one ...

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 11:57:46 am
content: Quote from: kripton2035 on June 23, 2014, 11:50:11 amNo offense taken if I always had the choice I would do this also

author: TerraHertz
author_rank: Super Contributor
timestamp: June 23, 2014, 12:48:17 pm
content: It was interesting to learn about progressive thread cutting taps (1 & 2 stripe) taps. Also funny to see the confusion among those who didn't get that taper and progressive are different things.I've been tapping holes all my life, and didn't know progressive thread-cut taps were available. Just the 3 end profiles: taper, intermediate and bottoming.Which, incidentally, you can make a bottoming tap out of either of the others with a grinder, going slow to not overheat and lose the temper.I don't think I'm ever likely to need to do progressive thread cutting. None of the machinist work I do needs that kind of sophistication. Mild steel, brass, aluminium, and very rarely a little stainless is all I ever use.Something I'm surprised no one has mentioned, is Trefolex. It's a lubricant grease intended for tapping.You don't need much - I was given a small vial of it by a machinist at my first job in my early 20's, and I'm still using that same vial, about 40 years later.But if it does run out before I die (unlikely) no worries. Since some years ago I found a huge tin of it, never used, rolling around loose in the junk on the floor of an abandoned brickworks' machinists shed. So I have about 20 lifetimes supply. Ha ha... since the place had been walk-through open to anyone for decades, and there was literally nothing else left there of any interest, I can only assume that no one else of the hundreds (thousands?) who must have wandered through knew what it was.This stuff:http://www.crcindustries.com.au/trefolex-cutting-compoundYou just dip the tap into it before cutting a thread.Another tip: if you are desperate to get a large screw or bolt into a material that is too tough to let you just force the screw in, but you don't have a tap, you can make an improvised tap out of one of the screws.Use a very thin cutting disk in an angle grinder, and cut a groove lengthwise along the body of the screw. If you do it carefully, at the right angle, you can get a good sharp 90 degree cutting edge on the 'advancing' face of the groove. Viola! A one-flute tap. Even though the screw likely isn't tempered, it will thread-cut a few holes into materials like aluminium or hard plastics. With hardened screws/bolts, they will even thread-cut into mild steel.For small taps like M3, 1/8" and below, I find it helps a lot to have a suitable small tap holder, that has only a short, fixed cross bar. Gives a much better feel for how the cut is going. Like the one at bottom-right in the pic.

author: neslekkim
author_rank: Super Contributor
timestamp: June 23, 2014, 12:51:01 pm
content: Quote from: kripton2035 on June 23, 2014, 11:11:00 amyes, I'm seeing it, found it around on ebay also, but the cheapest seller is on holiday, so I'll try to remember it after summer, thanks!

author: mzzj
author_rank: Super Contributor
timestamp: June 23, 2014, 12:54:09 pm
content: Quote from: kripton2035 on June 23, 2014, 11:11:00 amI bet only thing German is the nameMannesman is nowadays chinese crap re-branded. With luck you can get decent product like anything else made-in-china.

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 03:23:43 pm
content: I have other tap sets I bought in a shop nearby, they are single tap set, and they don't last long ...this one has 3 taps sets and for now it's still entirely not broken.we will see but it really seems stronger than all the others.

author: WarSim
author_rank: Frequent Contributor
timestamp: June 23, 2014, 03:33:49 pm
content: I have searched eBay.ca many times for the progressive type tap set. After using all the search terms I can think of I just can't find any. There could be some from Europe but the Canadian site will show thousands unrelated items long before it will show a non-USA item. Goofy site shows many USA only sellers before the Canadian sellers when the Canada only option is checked. It's pathetic.Nothing found on the industrial tool and die sites I found either.Seems I am trying out retirement I don't have access to a machine shop I don't have any other sources to try.Well, interesting thread, but I believe it is time to give up on finding a progressive tap set. There seems to be a mental block when it comes to anything but the tapper/plug/bottoming taps here in North America.Sent from my iPad using Tapatalk

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 04:25:01 pm
content: this one is for metric threads but it is available to ca ..?http://www.ebay.ca/itm/Tap-Die-Set-metric-32-pc-High-Speed-Steel-PRO-HSS-SET-FOR-NEW-THREADS-2316-/141031593246?pt=LH_DefaultDomain_3&hash=item20d623551e

author: WarSim
author_rank: Frequent Contributor
timestamp: June 23, 2014, 05:20:25 pm
content: Quote from: kripton2035 on June 23, 2014, 04:25:01 pmI zoomed in on the picture and they look like Tapper/Plug/Bottoming sets.Do you have information to the contrary?Sent from my iPad using Tapatalk

author: WarSim
author_rank: Frequent Contributor
timestamp: June 23, 2014, 05:23:18 pm
content: Quote from: WarSim on June 23, 2014, 05:20:25 pmI have also never heard of lape course, medium, fine used for anything but pitch.Sent from my iPad using Tapatalk

author: mzzj
author_rank: Super Contributor
timestamp: June 23, 2014, 06:30:47 pm
content: Quote from: WarSim on June 23, 2014, 03:33:49 pmI dont see much use for progressive taps anyways. Most of the high quality taps nowadays are machine taps and 3-piece set hand taps are more often some sort of chinese cr*p.Sometimes you can get slightly used high(superb) quality machine taps for almost free.AFAIK This side of pond(europe/finland) most of the 3-piece hand tap sets are progressive type. (and we mostly use machine taps even when working handheld)

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 06:46:09 pm
content: I ordered one of those sets kripton, for that price a bargain!

author: kripton2035
author_rank: Super Contributor
timestamp: June 23, 2014, 06:51:57 pm
content: Quote from: Kjelt on June 23, 2014, 06:46:09 pmI putted it in my wish list some times ago at 51€, then it was discounted at 32€ then I bought it it was 23€ and I got 15% more rebate for father's day !!!!I saw the same looking box (and it must be quite the same inside...) on another seller for 110€ ... no comment !

author: deth502
author_rank: Frequent Contributor
timestamp: June 23, 2014, 07:41:27 pm
content: Quote from: TerraHertz on June 23, 2014, 12:48:17 pmsame boat, like i said, electronics im a stupid hobbyist, but ive been a machinist for years, and that was the first ive heard of them.but again, as i mentioned, i have seen over/undersized taps. never saw the need for undersized, but oversized are used for items that you want to heat treat, as during the process, the metal around the hole will expand, and thereby, cause the hole to "shrink", so tapping the annealed project with an oversized tap is proper procedure.im wondering if these "progressive taps" are really made to be used progressively, or if they are just a set of std/under/over taps??

author: mzzj
author_rank: Super Contributor
timestamp: June 23, 2014, 08:00:51 pm
content: Quote from: deth502 on June 23, 2014, 07:41:27 pmYes they are made to be used "progressively". Sometimes the first tap has about half of the thread "missing" ie. thread is missing the peaks.For example I just measured M4 tap set diameters (probably RUKO, or something else made in germany)1. 3.6mm2. 3.8mm4. 4.0mm1. tap has about half of the threadform missing and trying to force M4 screw to the threaded hole is next to impossible.2. tap is still seriously undersize, with luck you can screw in bog standard M4 screw.Take a close look at these taps for example:

author: rob77
author_rank: Super Contributor
timestamp: June 23, 2014, 08:08:43 pm
content: Quote from: sync on June 17, 2014, 12:21:01 pmUS Guys - please read the whole thread - it was discussed already. the picture in the above quote explains it well.conclusion already made in the thread:US - those taps uncommon/rareEU - those taps are common except UK

author: Kjelt
author_rank: Super Contributor
timestamp: June 23, 2014, 08:31:03 pm
content: Quote from: kripton2035 on June 23, 2014, 06:51:57 pmIndeed a Great value, I also saw the 120 piece set of the same manufacturer now from 170 for 75 euro,s i was tempted but I have no use for imperial taps so i declined that one.

author: neslekkim
author_rank: Super Contributor
timestamp: June 23, 2014, 08:47:09 pm
content: Quote from: Kjelt on June 23, 2014, 08:31:03 pmIn older houses in Norway, we are using imperial threads on the electricity installations, almost hopeless to find new screws when you loose the ones for hanging lamps, or fixing the covers over the holes in the roofs/walls..Tools like this would help, but a whole set is somewhat overkill..

author: AlfBaz
author_rank: Super Contributor
timestamp: June 23, 2014, 11:23:12 pm
content: 8 pages about taps and tapping holes, impressive!

author: SeanB
author_rank: Super Contributor
timestamp: June 23, 2014, 11:29:41 pm
content: For that you need a M4 tap, and the right screws for it. Otherwise you can just buy the correct screws online in a long length and cut them down to size. You even get a thread cutting version of the screw here ( but always too short) included when you buy Clipsal outlets. It will rethread many of the outlets and works in plastic boxes as well.

author: deth502
author_rank: Frequent Contributor
timestamp: June 24, 2014, 12:07:13 am
content: Quote from: mzzj on June 23, 2014, 08:00:51 pmfirst good clear picture of them ive seen in this thread. definitely shows how they were designed to work.

author: SeanB
author_rank: Super Contributor
timestamp: June 24, 2014, 12:50:54 am
content: A lot of the cheaper taps are semi progressive, with the first tap being a gradual thread cut as it goes deeper into the hole. Each turn cuts the thread deeper into the material till the mid section of the tap is close to cutting the full thread. Then the following taps take this semi cut thread down to the bottom of the hole.

author: neslekkim
author_rank: Super Contributor
timestamp: June 24, 2014, 05:43:49 am
content: Quote from: SeanB on June 23, 2014, 11:29:41 pmI guess you where referring to my talk about the outlets?In my house, these boxes are of some metal, and put in the concrete walls, so I'm a bit worried about rethreading, but that is probably what I should have done

author: akis
author_rank: Frequent Contributor
timestamp: June 24, 2014, 10:34:54 am
content: Quote from: SeanB on June 24, 2014, 12:50:54 amThat makes absolute sense. When my Chinese taps arrive, bought from China, I will take pictures to see if they have progression. However a bottoming tap by definition cannot be an all-in-one progressive. So I suppose this only really matters for making blind holes where the threads need to go all the way to the bottom. Am I right?

author: VK5RC
author_rank: Unknown
timestamp: June 24, 2014, 12:42:46 pm
content: Yup, use the taper first then finish with the bottoming tap in the blind hole

author: SeanB
author_rank: Super Contributor
timestamp: June 24, 2014, 06:09:44 pm
content: Quote from: neslekkim on June 24, 2014, 05:43:49 amFunny enough I was doing a socket outlet in a metal wall box today, and used the included self threading screws to convert the socket outlet ears from the old imperial thread to a sort of metric thread. They were not happy on 2 of the ears, seeing as the last time those had a screw in them was when they were made in the early 1960's, so I went with the good old method and used 2 sheet metal screws instead of trying to persuade the steel screws to go in all the way, as they were getting very tight after around 5mm of thread. Black hard drywall screws worked a treat instead.

author: G7PSK
author_rank: Super Contributor
timestamp: June 24, 2014, 09:26:52 pm
content: I recently needed a 12mm x 1.25mm left hand tap when it arrived it was stamped made in England so there are tool makers still at work in the UK, And it was no more expensive than a Chinese tap or any other country made one either. Kingsland metal workers are made just up the road from here in Sheringham.It really anons me that so many people think that all manufacturing has departed from our shores just because when they go into Tesco's every thing is from China as there customers want cheap,cheap,cheap.

author: neslekkim
author_rank: Super Contributor
timestamp: June 25, 2014, 12:38:25 am
content: Quote from: SeanB on June 24, 2014, 06:09:44 pmThis building is from 1950-1960, but I need to find out what that translates to here, that is, Black hard drywall screws...Luckily we have one hardware store in the city that have stocked up on these screws, but it means about $2 pr screw

author: mzzj
author_rank: Super Contributor
timestamp: June 25, 2014, 06:02:09 pm
content: Quote from: neslekkim on June 25, 2014, 12:38:25 am

author: SeanB
author_rank: Super Contributor
timestamp: June 25, 2014, 06:41:58 pm
content: That is the one, drywall screw 22mm long, I used some that were slightly used, having come out of the old fixings. They are nice in that they are self drilling into thin metal, and I have drilled them into 1.2mm steel with moderate success. Power drivers tend to snap the heads off if you have too much torque, but in walling this is not much of a worry. To get clearance you need a 3.2mm drill, and if you want it to cut a thread in thicker material you need to drill between 2.5 and 2.8mm pilot holes, depending on thickness and the material. Wood and plastic it will pretty much self drill. Works quite well in composite wood products, but for chipboard they tend to have poorer performance than the correct chipboard screws. But if you put in enough of them it will do well.

author: robrenz
author_rank: Super Contributor
timestamp: June 25, 2014, 11:04:43 pm
content: I have tapped a few holes in my 49 years of machining. Here are a fewopinions.In the US, serial or progressive taps are usually only used for difficult thread forms like Acme, Buttress, or Square. These are often supplied in a single tap that has rough and finish sections both of which are a long taper style as shown in this Acme thread form tap. Spiral point and spiral flute taps are so efficient that there is no need for progressive/serial tapping on even the toughest materials for regular "V" thread forms.Hand taps suck. They generally can't be used effectively in a tapping head. I only use them when it is the only thing available in a thread size. The exception being a bottom tap which should only be used in a previously tapped hole to get full form threads closer to the hole bottom. A bottom tap is not meant to tap a hole by itself as the first tap used. Hand taps do like/need to be backed off frequently to clear chips.The taper style hand tap accomplishes basically the same thing as the serial tap set because the very long shallow taper makes the radial depth of cut of each tooth very small compared to a plug taper tap. But you have to be doing a thru hole for that to work.Spiral point taps (plug style) I use the most and are best on thru holes as they push continuous chips ahead of the tap. They can be used on blind holes also but chips can pack at the bottom of the hole and can be difficult to remove. Even if I am tapping by hand or using a hand drill as a tap driver I use a spiral point tap.Spiral flute taps (plug style) I use on blind holes, I would not reccomend hand tapping with them. These force continuous chips back out of the hole following the spiral flutes. But those spiral flutes make for a much weaker tap and are easier to break.My favorite lubes are Tap Magic Aluminum for Aluminum and copper and Cool Tool II with 15% Castrol Moly Dee added for all other ferrous materials.I like thread forming taps and even use them to do 0-80 holes in aluminum. Tap hole size is more critical and it must be a ductile material. But a tapping head and a good lube is a must to tap with these.The biggest thing I have learned is that you get what you pay for in taps. I tap a even mix of mild steel, A2 tool steel and Ductile Iron. I used to by $5.00 to $10.00 taps and they worked ok and would last several hundred holes before the torque would get excessive from general wear or chipping. Now I buy much higher quality taps that are in the $15.00 to $25.00 range. These taps last for many thousands of holes by comparison and the torque does not change significantly over the life of the tap. You are paying for higher quality particle metalurgy tool steels and radial relief of the thread form itself.I had a job making parts from Viscount 44 which is H13 tool steel pre heatreated to 44 rockwell C scale and also M42 tool steel. Both pretty tough stuff to tap. The parts had 6-40 tapped holes. I used my normal $10.00 taps and got about 6 to 10 holes per tap. So I thought lets see if these super taps are really any good. I bought a $28.00 tap designed for hardened tool steels and it has done multiple hundreds of holes and still looks brand new. These arent even the very high end taps which are in the $25.00 to $60.00 rangeFWIW

author: Monkeh
author_rank: Super Contributor
timestamp: June 26, 2014, 06:58:50 pm
content: I wondered when robrenz would reappear in this threadOn a totally different subject, you might find this interesting if you haven't seen it before:

author: robrenz
author_rank: Super Contributor
timestamp: June 26, 2014, 07:48:35 pm
content: I saw some like that about 30 years ago that showed different cutting edge geometries and conditions and how they imparted tensile or compressive residual forces in the cut surface. It was very enlightening being spoon fed a mental picture of what was going on.