- Our SHOCKWAVE Impact Duty Mechanical Step Bits are engineered to deliver the most durable and fastest impact step bit hole drilling solution. Our step drill bits are made in the USA with global materials and give you best-in-class performance in impact drivers with the versatility to be used in drills. The ¼ in hex shank has an optimized SHOCKZONE body providing you with the industry’s most durable shank, reducing early shank breaks. A Titanium Aluminum Nitride (TiAlN) coating helps deliver you 5x longer life, while the step drill bit's Rapid Strike tip and dual spiral flute produce 2x faster holes. Our step drill bit kit features the #2 3/16 - 1/2 in, #3 3/16 - 3/4 in, and #8 1/8 - 1 in step bits with laser engraving for a clear stop on size identification.