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Irwin Unibit 6 in. L High Speed Steel Step Drill Bit Square Shank

Made in America

Support American manufacturers + independent hardware retailers in one purchase.

One bit, multiple hole sizes - high speed steel construction handles sheet metal and thin stock without switching tools.
Irwin MPN 10220 In Stock & Ready to Ship
$59.99
Free shipping on orders over $75
Ships within 24 hours · most orders arrive in about 2 business days

About Product Overview

The Unibit #20 from IRWIN is a step drill bit built to handle multiple hole sizes without switching tools mid-job. Made from high speed steel, it's designed for drilling through sheet metal, plastic, and other thin materials where a standard twist bit would grab or tear the edges. The stepped design lets you drill a pilot hole and then open it up to larger diameters in stages, all with one bit chucked in the drill.

The 7/16-inch square shank fits standard drill chucks securely and resists slipping under torque, which matters when you're working through metal. At 6 inches overall, it gives you enough reach for most electrical, HVAC, and fabrication tasks. It ships carded as a single bit, made in the USA, so it's easy to keep as a dedicated tool in a truck box or shop drawer.

  • Material: High Speed Steel
  • Product Type: Step Drill Bit
  • Shank Type: Square Shank, 7/16 inch diameter
  • Overall Length: 6 inches
  • Package: 1 bit, carded
  • Made in USA

The Details Specifications

Brand Irwin
Model / MPN 10220
UPC 038548102207
Weight Under 1 lb
Country of Origin USA
Safety Data Sheet (SDS) Manufacturer documentation · opens in new tab
Price check

Go ahead. Check.

You're going to price-check us against Amazon, Home Depot, and Lowe's. Everybody does. Good — open all three tabs. We'll wait. Then look hard at what you're actually being handed over there.

On Amazon, start with these four questions before you click buy.

01

Who's actually selling it

The brand name is on the listing. A different company is in the seller field. Those aren't the same thing, and the second one is who you're buying from.

02

Whether the warranty survives

Most manufacturers only honor a warranty when the unit came through an authorized dealer. We're authorized for Irwin. A third-party marketplace seller usually isn't.

03

Where the box came from

Gray-market stock, returns repackaged as new, and outright fakes move through marketplaces constantly. It all looks identical in the photo. It stops looking identical when it fails.

04

Who you call when it breaks

Ours is a phone number with a person behind it who has held this product. M–F, 6 AM – 5 PM Pacific. (866) 469-8556

The big boxes don't care if your hardware store survives.

Amazon, Home Depot, and Lowe's are built to pull every hardware dollar out of your town. When the local shop can't keep the lights on, the counter where somebody actually knew which part you needed goes with it. We're built the other way: real brands so you're never stuck on a marketplace, and a straight answer to buy it down the street when that's the better call. Support independent hardware — it doesn't restock itself.

Why we tell you to shop local
Authorized dealer · Irwin

Or skip the tabs entirely and buy it down the street. Find a store near you →

Shop Local · Support Independent

Every order helps keep your local hardware store on the corner.

Why we built NHG
You might find it for less locally. Independent retailers often offer competitive pricing — some products are even cheaper in-store than online.
Real expert advice — not search results. Independent hardware staff know their inventory and the local conditions you're working in.
Keep the neighborhood working. Every dollar spent at an independent retailer returns roughly 3x more to your local economy than at a national chain.

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