Irwin IRW10221 Drill Bit Set 10

The Irwin IRW10221 is a UNIBIT MAX step drill bit, 13/16 inch minimum to 1-3/8 inch maximum diameter, 1/16 inch incremental diameter, with a 1/2 inch shank, cutting 10 hole sizes, for material thickness up to 1/8 inch.

A step drill is a cone of progressively larger cutting steps, and it does something a twist drill cannot do well: cut a clean round hole in thin material. A twist drill in sheet metal grabs as it breaks through, tears a triangular hole, and throws the workpiece. A step drill's geometry cuts progressively and self-centres, leaving a round hole with a deburred edge.

The other advantage is that one bit replaces ten. Drilling ten different hole sizes in sheet conventionally means ten twist drills, ten changes, and a pilot hole for each. A step drill starts small and simply goes deeper for a bigger hole.

The 13/16 to 1-3/8 inch range is the large end of the step drill scale — conduit knockouts, panel entries, and large penetrations rather than small fixing holes.

The 1/8 inch maximum material thickness is the specification to respect. Step drills cut with the edge of a step, and thicker material than the step's height means the step cannot cut cleanly.

The 1/2 inch shank suits a substantial drill.

Applications include electrical panel and enclosure work, HVAC ductwork, sheet metal, and autobody.

Brand

Irwin

SKU

IRW10221

Category

Power Tools & Accessories

Weight

1.1 lbs

Dimensions

10.00 x 2.25 x 0.75

Price

$143.00

Availability

In stock

Rating

3.79 / 5.0