ROSNEK 2PCS HSS M35 Cobalt Twist Drill Bits HSS-Co Bit 5% Co For Metal Drilling 8mm

ROSNEK 2PCS HSS M35 Cobalt Twist Drill Bits HSS-Co Bit 5%Co For Metal Drilling 8mm Feature 1. 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.With molybdenum and cobalt added to creates a hardened alloy, measuring Rockwell hardness up to 68, extremely heat resistant; for much faster cutting and extra longer life span, with  up to 12 times when compared with an average HSS drill bit. 2. 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. 3. The 135° Quick-Cut points are self-centering and penetrate quickly with less pressure. Will not "walk" or "wander". Straight shank allows for firmly holding and accurate centering, fit for standard drill chucks and regular round collect chucks. Must be used and operated at proper RPMs for maximum efficiency. 4.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. 5. It's a common sense that harder stuffs are more brittle. While the 5% cobalt makes the bits much more durable as well as giving them an abrasive quality, it also makes them more brittle than ordinary HSS bits. Package 2pcs of 8mm HSS-Co-M35 Twist Drill Bit