M35 & M42 provides better wear resistance, higher hardness and toughness than HSS. M35 has some of the increased red-hardness properties of M42 and it's not as susceptible to shock. M42 has excellent resistance to abrasion and very good red-hardness for working on cast iron, heat-treated steels and titanium alloys. Cobalt drill bit also has very little chipping or microchipping under severe cutting conditions, allowing tool to run 10% faster than HSS. Cobalt drill set comes in American made, rugged all steel drill index case from Huot Manufacturing.
135° Self-centering Split Point prevents walking when starting a hole and is commonly on heavy duty tools.
Heavy duty drill bit usually combine a split point to prevent walking and stronger flute for better rigidity. Excellent choice for harder material.
Conclusion: Industrial grade M35 cobalt drill has performed 266 numbers of holes before showing normal wear. Shars industrial grade HSS6542 drill has performed 194 numbers of holes before showing normal wear while generic import grade HSS4241 tin coated drill from company A has performed 80 numbers of holes before showing edge chipping.
Grade M35 drill set from Shars Tool has shown significant improvement in tool life than other generic import drills on the market.