This Irwin 15 Piece drill bit set is a black oxide high speed steel, fractional straight shank jobbers length. The 118 degree tip drill bit set comes in a metal index for safe storage of your drill bits. The bits range from 1/16" through 1/2" by 32nds. These drill bits can be used in applications such as construction, maintenance and repair, electrical, plumbing, and medium duty production lines.