M35 Cobalt Drill Bits Hss Co for Stainless Steel

M35 cobalt drill bits are designed for high-heat, high-friction industrial drilling. They are ideal for drilling tough materials such as 304/316 stainless steel, titanium alloys, cast iron, and high-tensile steels. With superior heat resistance and durability, they are widely used in automotive repair, heavy-duty metalworking , and aerospace fabrication where standard HSS bits wear out quickly.

M35 refers to a specific grade of High-Speed Steel alloyed with 5% Cobalt (HSS-E). In the AISI classification system, M35 signifies a balanced metallurgical composition that enhances the bit's "red hardness." At Tenyu Tool, our M35 series undergoes advanced vacuum heat treatment to reach a Rockwell hardness of 65-67 HRC or higher, ensuring the cutting edges remain sharp even when the tool is glowing at high operating temperatures.

Yes, Their primary advantage is longevity and heat resistance. While more expensive than standard HSS, an M35 bit can outlast regular bits by up to 10 times when drilling hard metals. For B2B procurement, this translates to fewer tool changes, reduced downtime, and a significantly lower cost-per-hole in high-volume production.

The difference lies in the Cobalt content and its trade-off between hardness and toughness:M35 (5% Cobalt): Offers a perfect balance. It is hard enough for most stainless steel applications while retaining enough toughness to resist snapping under manual drilling or slight vibrations.M42 (8% Cobalt): Achieves even higher hardness (often reaching 68 HRC). However, M42 is more brittle. It is ideal for rigid CNC setups and super-alloys but may fracture more easily in handheld drills compared to the more resilient M35.

Absolutely. M35 bits are cobalt-alloyed throughout the entire body. This means you can resharpen the point multiple times using a bench grinder or a professional sharpener, and the bit will retain its full 5% cobalt properties and 67 HRC+ hardness. This makes them a highly sustainable and cost-effective investment for long-term industrial use.

Due to their extreme hardness, they are less flexible than standard HSS. They can snap if the drill is tilted or if the workpiece is not securely clamped.The cost of cobalt as a raw material.