Save the usable inner part of a worn disc. These tools work like a can opener to trim the perimeter of the disc down to the next smaller size. Trimmers are compatible with all replacement blades.

Trimmers for ceramic alumina and zirconia alumina have blades that are cryogenically treated. Freezing temperatures are used to harden the blades and increase their wear resistance, so they can cut through tougher abrasives than untreated blades.