IRWIN Unibit 10502ZR Step Drill Bit Set, 1/8'' to 3/4'', 3-Piece

The IRWIN Unibit® 3-piece Set contains the #1, #2 and #3 step drill bits which allow for a total of 28 hole sizes from 1/8" to 3/4". They are designed to drill perfectly round holes in thin materials with less effort than other bits. They also drill through wood, composition board plus plexiglass and plastics that often crack with conventional bits. The high-speed steel fractional self-starting drill bits will cut steps of progressively larger diameters. Cutting edge enters one step at a time to cut rapidly in small bites without over-taxing motor.

Use all-around Unibit #1 for most common drilling jobs. Drill 13 hole sizes (1/8"-1/2" diameter in 1/32" increments) with 1/4" shank, 1/8" step thickness. The #2 drills standard hole sizes in materials up to 3/8" thick. With 1/4" shank, 3/8" thickness, drill six sizes (3/16"-1/2" in 1/16" increments). Use #3 for medium-sized holes. Drill nine sizes (1/4"-3/4" in 1/16" increments) with 3/8" shank, 1/8" thickness.