Milwaukee 's SHOCKWAVE Impact Duty step bits are engineered to deliver the most durable and fastest holes in the market. Made in the USA with global materials, these step bits have best-in-class performance in impact drivers and the versatility to be used in drills. The 1/4 in. hex shank with an optimized Shockzone provide the industry's most durable shank, reducing early shank breaks. A titanium aluminum nitride (TiBone) coating helps deliver 5x longer life, while the Rapid Strike tip and dual spiral flute produces 2x faster holes.