3/8, Cobalt End Mills, 4 Flute - Center Cutting - Square End, 30&ordm; Helix 3/8 DIA. X 3/8 SHK DIA. X 3/4 LOC X 2-1/2 OAL - 4 FLUTES - A57353 Cobalt End Mills 4 Flute - Center Cutting - Square End 30 Helix