Sorby TurnMaster Carbide Round Cutter

Tungsten Carbide – Made of 50% Tungsten and 50% Carbide with a Cobalt filler, it has a hardness of 90RC. While it will not take as keen an edge, it will hold an edge the longest. Most people just replace the cutter when it dulls. Micro Grain Tungsten Carbide can be sharpened to between 0.7 to 1 microns.