M42 Tersa knife blades are a grade of high speed steel with a high content of cobalt in the alloy. It is less brittle than carbide steels. Similar to nickel in hardness and durability Cobalt increases hardness, edge life and heat resistance.
Molybdenum: produces toughness and neutralizes brittleness of chromium. Also helps increase edge life. The difference between the M42 and the regular HSS Tersa knives is most noticeable in the footage obtained from a set before they
