1" Nikasil Applications Hones are made with a softer material, Aluminum Oxide. These special hones are required for todays coated aluminum cylinders. These aluminum oxide hones are recommended for nikasil and chrome coated cylinder bores. Grits of 120, 180, 240, 320, 400 available. 80 and 600 grits available special order. The overall tool length is 8".