How to Cut Corrugated Metal in Any Direction

If you've ever needed to cut a vent, pipe pass-through, or any kind of interior opening in a corrugated metal panel, you already know the problem: most tools can't start a cut in the middle of a sheet. Tin snips work fine on the edge, but they can't punch in. Jigsaws bind in the corrugations. Circular saws throw sparks and leave chewed-up burrs. What you actually need is a way to cut corrugated metal in any direction, straight, curved, or anywhere in between, without a fight.

That's exactly what the Bad Dog Biter does. With one starter hole and the Biter chucked in your drill, you can cut a clean opening anywhere on the panel. Here's the two-step method.

Why Cutting Corrugated Metal Is Harder Than It Looks

Corrugated panels aren't flat steel. The ridges flex, vibrate, and grab any blade that isn't built for them. Standard metal-cutting tools have their place. But most of them are made for edge cuts, not interior cutouts.

• Tin snips and aviation shears can't start a cut in the middle of a panel
• Jigsaws want to bind on the ribs, especially on tight curves
• Circular saws with metal-cutting blades are loud, throw hot sparks, and leave rough burrs that need cleanup
• Angle grinders work but heat the panel and can damage galvanized coatings

The Bad Dog Biter solves it differently. It chucks into any standard drill, drops into a 1/2" starter hole, and rolls through the metal as you guide it. Flat sheet, ridges, curves, none of it stops the bit.

The 2-Step Method: Starter Hole Plus Biter

Here's the whole process in one breath: drill a 1/2" hole, drop the Biter in, cut. That's it. Once the Biter is seated in the starter hole, you can go in any direction you want to go. You can cut straight lines, tight curves, and full circles for round openings.

The starter hole has to be a clean 1/2". That's where the Bad Dog Stubbies come in.

Step 1 — Drill a 1/2" Starter Hole With a Bad Dog Stubby

The Stubby is a short cobalt step bit. Drop it in your drill, line up where you want the opening, and step it up to 1/2". Done.

A few reasons the Stubby is the right bit for this job:

• Short profile — fits in tight spots where a standard-length step bit can't reach
• Cobalt construction — built to handle steel, stainless, and other tough materials
• Locking extensions — when you do need length, you get it without sacrificing rigidity
• One bit, multiple sizes — useful for the rest of the job too, not just this one hole

Mark your spot, support the panel from underneath, drill straight through to the 1/2" step. You'll have a clean entry point ready for the Biter.

Step 2 — Drop the Bad Dog Biter in the Hole and Cut

Pull the Stubby out, swap in the Biter, drop it into the hole. The Biter rolls right in. From there, you guide the cut. Straight, curved, anywhere on the panel.

A few things worth knowing about the Biter:

• Under one pound — it doesn't fight you, so you can run long cuts without your arm giving out
• Roughly 2,000 feet of cutting per blade set on 18-gauge mild steel — a lot of corrugated panel before you swap blades
• Cuts in any direction — no need to back out and re-enter for curves
• Standard drill chuck — no special tools, no special drill, just chuck it up

The Biter doesn't care which way you go. Trace your cut line and follow it.

Pro Tips for Cutting Corrugated Metal

• Mark your line first. Don't freehand it. A clear line gives the Biter something to follow and saves you from creeping off-course.
• Support the panel. Corrugated metal flexes. A bit of support under the cut zone keeps the panel from chattering and gives you a cleaner result.
• Slow down on tight curves. The Biter will go where you point it, but it works best with steady pressure rather than forced direction changes.
• Let the tool pull itself along. Don't muscle it. Keep the bit seated and let it track through the metal.
• Wear gloves. Cut metal edges are sharp until you deburr them.

Frequently Asked Questions