M42 is a great material for use on cutting tools such as bandsaw blades, taps, milling cutting inserts. It has a great balance of toughness and hardness for the given applications. An additional 8% cobalt allows for very good red hardness relative to M2. As mentioned M42 has the ability to deliver exceptional cutting performance. M42 can achieve a hardness between 68 - 70 HRC.
AISI ASTM A681
BS EN ISO 4957