M42 HSS: The Science | Carter and Son Toolworks
M42 high speed steel has been used for centuries in shops of all kinds, from enormous factories to your personal woodturning shop. M42 high speed steel has a unique structure, allowing its trademark durability and edge sharpness. A 10% additive of cobalt is responsible for M42's toughness. Cobalt allows heattreatment up to 6468 HRC.