M35 Cobalt Drill Bit Set for Stainless Steel Drilling High Heat Resistance Applications

This M35 cobalt drill bit set is purpose-built for the toughest drilling challenge in metalworking: stainless steel. The addition of 5% cobalt to the high speed steel matrix substantially improves red hardness, allowing the cutting edges to retain their strength at elevated temperatures where ordinary HSS bits soften and fail quickly. This makes the set an essential choice for fabricators, pipe fitters, shipyards and maintenance teams that regularly drill into 304, 316 and other austenitic stainless steels.

Each bit features a 135-degree split point for accurate starts and a hardened structure reaching HRC 65-67, combined with flute geometry designed to move chips aggressively out of the cut. The result is faster penetration, cleaner holes and dramatically longer tool life in heat-intensive applications. When workpieces and cutting edges stay cooler, the risk of work hardening the stainless surface is reduced, which is a key factor in successful stainless steel drilling.

• 5% Cobalt M35 Grade: Enhanced red hardness keeps edges cutting when friction heats the tool during stainless steel drilling.
• Heat Resistance to 600°C: Maintains cutting performance at temperatures that rapidly destroy standard HSS drill bits.
• 135° Split Point: Self-centering start prevents walking on smooth stainless surfaces and reduces required feed pressure.
• Hardness HRC 65-67: Optimized for abrasive and work-hardening materials, delivering extended service life.
• Aggressive Chip Evacuation: Flute geometry clears stringy stainless chips quickly, preventing clogging and heat concentration.
• Versatile Set Range: Metric sizes from 1.0 mm to 13.0 mm cover common stainless steel fastening and fabrication jobs.

The primary application of this M35 cobalt set is drilling stainless steel plate, pipe, sheet and structural sections in fabrication shops, shipbuilding yards, food processing equipment plants and chemical industry maintenance. It is also effective on titanium alloys, nickel alloys and hardened steels that defeat standard HSS tooling. Plumbers and HVAC contractors use these bits for drilling stainless sinks, ductwork and commercial kitchen equipment.

For best results, operators should use moderate speeds with steady feed and a suitable cutting fluid or paste. Under these conditions the cobalt bits produce clean, round holes with minimal burr formation and resist the edge breakdown that causes premature failure. This combination of heat resistance and durability makes the set a cost-effective investment for any operation that works with stainless steel regularly.

This set ships in a durable plastic case with labeled size slots, packed in a strong export carton with protective inserts. We provide OEM services including custom size combinations, private label printing and branded cases. Each lot is verified through hardness testing, geometry checks and performance drilling on stainless steel samples before shipment.

Our manufacturing facility applies strict process control from raw material selection to final inspection, ensuring consistent quality across every batch. We offer attractive factory prices for wholesale and distribution partners, with flexible payment terms and reliable logistics. Send us your inquiry to receive a detailed quotation and delivery plan.