Grade M42
Grade M42 is a cobalt-based high-speed steel (HSS) with 8% cobalt, specifically engineered for extreme high-speed cutting applications. It is one of the highest-performance HSS grades available, combining exceptional wear resistance, red hardness, toughness, and strength at elevated temperatures.
M42 is widely used in precision machining, tool-making, and manufacturing industries, where cutting tools must endure high-speed operations, hard metals, and challenging materials. Its high cobalt content provides superior hot hardness, allowing tools to retain cutting edge integrity even at temperatures up to 700°C.
Key Properties of M42 HSS
1. Exceptional Hot Hardness & Red Hardness
a. Maintains hardness at temperatures up to 700°C
b. Typical hardness after heat treatment: 64–66 HRC
2. Superior Wear Resistance
High cobalt and carbide content ensures extremely long tool life under high-speed and abrasive machining.3. High Toughness
M42 combines hardness with resistance to chipping, ideal for heavy-duty cutting or interrupted cuts.4. Heat Treatable
a. Hardened at 1220–1230°C and tempered 3–4 times
b. Optimized balance between hardness, toughness, and wear resistance
5. Machinability
Machinable in annealed condition; post-hardening used for drills, taps, end mills, and broaches.Typical Applications of M42 HSS
1. High-performance twist drills, taps, reamers, and milling cutters
2. End mills, broaches, gear cutters, and cutting tools
3. Tools for stainless steel, alloy steel, and high-strength metals
4. Precision industrial cutting in aerospace, automotive, and tool-making industries
5. Heavy-duty machining requiring maximum wear resistance and high-temperature performance