Hymnorq M35 Cobalt Steel Fractional 9/32 Inch Dia. x 4.25 Inch Long Twist Drill Bit Set of 5pcs, Jobber Length Round Shank, Self-centering Split Point, Heat Resistant for Metalworking
Brand: HYMNORQ
M35 Grade Cobalt Steel
Cobalt drill bits are not made of pure cobalt, but rather a steel alloy with certain percent cobalt. The 5-percent alloy is known as M35 grade. The cobalt increases the strength of the steel and makes it more heat-resistant.
135 Degree Split Point
The flater the drill, the smaller the chip width. This means less force required to remove metal, compared with lower angles like 90° and 118°. This is important on hard stuff, because your power requirements are already more than mild steel, so making the chip load less helps. It also reduces heat since less surface area is generating the cut.
Lowest Cost Per Hole Drilled
Cobalt drill bits are more expensive than other drill bits, but if you regularly drill through metal, they are a good investment since they tend to last longer. With an extended tool life, Hymnorq cobalt drill bits will give you the lowest cost per hole drilled.
For Drilling Stainless Steel
This set of M35 cobalt steel drill bits are particularly successful in cutting through hard metals such as stainless steel and cast iron, although they can be used for softer materials, too.

Tests shows that the M35 cobalt steel drill bits can penetrate a 5mm-thick 304 stainless steel plate in 5 seconds.
Not Suitable for Hardened Steel
M35 grade cobalt drill bits are NOT suitable for hardened steel, high carbon steel and heat-treated steel by the experiences of some customers, although some others said they worked well with hardened steel.
Cooling Liquid Required

Please use with cooling liquid to prolong the working life of the drill bits and to avoid overheating and breakage.
BUY WITH CONFIDENCE:
If you’re not completely satisfied with the product quality, please contact us. Refund or free replacement.
COBALT STEEL - Manufactured from M35 grade cobalt steel, with molybdenum and cobalt added to creates a hardened alloy, measuring Rockwell hardness up to 67, for much faster cutting and extra longer life span, with up to twelve times when compared with an average HSS drill bit.
FOR METALWORKING - Particularly successful in cutting through hard metals(hardness less than HRC38°) such as stainless steel and cast iron, although they can be used for softer materials like copper and aluminium, too. Not for hardened steel / high carbon steel. Try to adjust the RPM when it fails to penetrate.
SELF CENTERING - The 135°quick-cut pilot split points are self-centering and can penetrate quickly with less pressure. The bits will not "walk" or "wander". Straight shank allows for firmly holding and accurate centering, fit for standard drill chucks and regular round collet chucks.
5PC SET - The set includes 5pcs of 9/32” diameter M35 grade cobalt steel twist drill bits, packed in a plastic case for easy storage and carrying. Total lenght: 4.25 inch; working length: 2.95 inch. Manufactured to German DIN338 standard.
DOWNLOADABLE USER GUIDE - We've summed up some tips of drilling metals, including a RPM chart for several common metals, based on our reviews and some articles on the internet. In most cases, our customers would get a much better result with these tips. Welcome to download.