STROTON Metric M42 8% Cobalt Twist Drill Bits Set for Stainless Steel and Hard Metal (1.5mm-6.5mm/13pcs) Why choose STROTON cobalt drill bits? The research shows that HSS with cobalt has a higher temperature resistance and Red hardness, a greater wear resistance(Hardness) and a higher heat treat response than HSS without cobalt . Red hardness, it causes the hardened steel to have an ability to maintain hardness at approximately 860-880 .Higher Tempering resistance,it means to maintain a high hardness at high temperatures for an extended period of time.68-70 HRC,it means that the drill bits has 3X cutting ability and 2X durability.This drill bits set is made of Premium Cobalt (80,000 dollars per ton). M42 Cobalt 8% Alloy This drill bits set is made of Premium Cobalt (80,000 dollars per ton).
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