The Milwaukee SHOCKWAVE Impact Duty Electrical Step Bits are engineered to deliver the most durable and fastest impact step bit hole drilling solution. The step drill bits are global materials and deliver best-in-class performance in impact drivers with the versatility to be used in drills. The hex shank has an optimized SHOCKZONE body providing the industry's most durable shank, reducing early shank breaks. A Titanium Aluminum Nitride (TiAlN) coating delivers 5x longer life, while the step drill bit's Rapid Strike tip and dual spiral flute produce 2x faster holes. The step drill bit kit features the #1 1/8 - 1/2 in., #4 3/16 - 7/8 in. and #9 7/8 in. and 1-1/8 in. step bits with laser engraving for a clear stop on size identification.