This heavy-duty screw machine drill bit is made of high speed steel and has a 15/64 inch diameter, 1⅛ inch long shank. It is for use with cast iron, steel, and meets the standards for NAS 907 Type C. This 2330 series screw machine length drill bit has a bright (uncoated) finish, and has letter measurements. It is non-coolant through with a 2½ inch length. Plus it has two 1⅜ inch spiral flutes, a straight shank, and a 135 Degrees split point.