Grinding and Sharpening CPM 20CV: Belt Recommendations & Technique

CPM 20CV sits alongside CPM S30V and CPM M4 among the more demanding steels in this database to grind and sharpen. The same heavy chromium-vanadium carbide load that gives it exceptional edge retention also means belts load and dull faster than on tougher, easier-working steels like MagnaCut or Elmax, and standard sharpening stones struggle to cut its carbides once it is hardened.

Belt Selection

Ceramic belts are essentially mandatory for CPM 20CV, the same recommendation that applies to other high-carbide CPM steels like S30V. Zirconia or aluminum oxide belts will work, but wear out noticeably faster and cut more slowly on this steel’s dense carbide structure. Budget for more belts per knife than you would with a tougher, easier-grinding steel.

Grit Progression

A practical progression after heat treat looks similar to other premium stainless steels, just expect to change belts more often along the way:

Technique

Use higher belt speed with light, controlled passes rather than heavy, slow pressure, which loads the belt faster without cutting any more effectively. Keep a belt eraser or dressing stick close by and clean the belt regularly. A generous coolant mister helps prevent overheating, both for the edge and for belt life, since CPM 20CV’s demanding heat treat (see the heat treat details further down this page) means preserving the temper during grinding matters even more than usual.

Sharpening

Standard aluminum oxide or ceramic stones struggle to cut CPM 20CV’s carbide structure efficiently once hardened. Diamond stones are the clear recommendation for reprofiling and touch-ups, cutting cleanly through the carbides rather than just burnishing over them. A practical progression many sharpeners use is a coarse diamond or waterstone in the 1000-1200 grit range, followed by a medium stone around 5000 grit, then stropping with diamond compound for a final polish. Ceramic hones can work for light touch-ups between full sharpenings, but are not a substitute for diamond abrasives when the edge needs real correction.