Irwin 10234 #4 Unibit Step Drill 3/16-7/8 Inch High Speed Steel 12 steps

Single-Flute Cutting Edge For Greater Control Through Steps. Hex Shank Prevents Slipping In Drill Chuck. New Speedpoint Tip Penetrates Faster Than Previous Unibits And Prevents Walking. Ideal For Drilling Holes Into Thin Materials Such As Stainless Steel, Copper, Brass, Aluminum, Plastic And Laminates.