The Matco Tools 21-pc Hyper-Step Quick-Change High Speed Steel Stubby Drill Bit Set, No. DBQC21HSBS, measures from 1/16" to 3/8" by 64ths. The bits are coated with PVD to prevent chip adhesion and reduce the heat buildup from using impact drivers with high RPM. Each bit measures 1/4", smaller than traditional drill bits, for increased access to tight spaces and bit rigidity. The Hyper-Step design eliminates the need for pilot holes, easily creates neat holes in sheet metal and hardened metal, and prevents the bit from walking on curved surfaces. Bits 17/64" and larger come with a lifetime warranty.