For grinding FACES ONLY. The solid ball stops with 15-1/2° spacing allow fast and easy setups for sharpening 2, 3, 4, 6 and 8 flute end mills. The fixture uses 5-C collets so that all end mills with shank diameters from 1/16" through 1-1/8" can be ground. Clearance and relief angles are built into solid 2-1/2" x 4-1/2" base having a ground bottom.