Family of steels designed to hold an edge even when heated red hot by friction. While this is less likely to happen to your knife in everyday use, some of these steels have very high wear resistance. M2 tool steel or M4 tool steel for example. Though high speed tools at high hardness become rather brittle, thus not appropriate for large blades. However, when heat treatede properly M4 performs very well in large, heavy duty blades. Steels designed to machine other steels. These machine tools will hold an edge even when heated red hot by friction.
By webtech /