THINKWORK Four Spiral Flute Step Drill Bit, HSS Step Drill Bit3/16-1-3/8 (3 Popular Sizes) Unibit Step Drill Bit, 1/4″ Shank Step Bits for Aluminum, Wood, Plastic, Metal 3/16-1-3/8″

A 3-piece THINKWORK step drill bit set built for cleaner, more controlled hole enlargement—featuring four spiral flutes, laser-engraved step markings, and a 1/4″ straight shank. Covers 3/16″ to 1-3/8″ for common DIY and shop tasks in metal, wood, and plastic.