Made of M35 steel, 5 percent cobalt, with extra thick drill core for rigidity and strength Used in applications such as stainless steel and space age alloys All sizes 3/16 in. and larger have 3 flats on the shank for a better grip on the drill bit The 135 degree split point eliminates the need for a center punch and keeps the drill from skating on hard materials Includes (1) one each: 5/64 in., 3/32 in., 7/64 in., 9/64 in., 5/32 in., 11/64 in., 3/16 in., 13/64 in., 7/32 in., 15/64 in., 1/4 in., 5/16 in., 3/8 in., (2) two each: 1/16 in., 1/8 in., and a plastic case with rubberized grip panels.