Make Circles with the Biter LEASH
How-To Make Circles with the Biter LEASH
Off leash, the Bad Dog Biter Drill Mounted Sheet Material Cutter cuts like a champ. Freehand just about any design.
But sometimes tolerances demand laser-straight cuts or precise curves.
That’s when you snap on the Bad Dog Biter Leash.
The Leash works as both a trim gauge and a circle-cutting jig for straight lines in sheet metal, or arcs and circles up to 12" diameter. If you’re cutting ducts, doing bodywork, or fabricating custom panels, the Leash helps you cut faster, cleaner, and more precisely — every time.
What the Biter Leash Does
The Leash is a three-piece set that utilizes a threaded cutting head which holds a 6" hardened rod with an elongated stylus.
For trim work, the stylus glides along the edge of rigid sheet material so you can reproduce matching cuts with dead-on consistency.
Need an arc or circle? Anchor that same stylus in the center of your material and rotate the tool smoothly
for amazingly accurate arcs and circles from 2" up to 12" diameter.
- Radius = 1/2 diameter
- Extends up to 6" radius
- Cuts 2–12" perfect circles
Straight cuts. Perfect arcs. No guesswork.
Installing Your Bad Dog Biter Leash
Easy as 1-2-3
- Loosen the set screw and remove the cutting head, leaving the central cutting blade in place.
- Place the Biter Leash circle cutter over the blade and tighten the set screw.
- Adjust the guide arm’s position to create perfect circles or straight trim cuts.
Slide the adjustable guide arm inward for smaller circles. Extend it outward for larger ones.
For circle cutting, anchor the stylus at center and rotate steadily.
For trim work, let the stylus ride the sheet edge and keep smooth forward pressure.
That’s it. One set screw. Quick swap. Back to work.
Why the Bad Dog Leash Is a Cut Above
- Works with all Biter models
- Adjustable for circles up to 12" diameter
- Quick install — replaces existing Biter head
- Hardened steel construction for long-term accuracy
- Elongated stylus for no-slip tracking
- Compact and lightweight
- Ideal for HVAC, auto body, and fabrication work
Use the Leash attachment for perfect circles with every cut.
Less bark. More bite.
Written by Joseph Strong on 11th Feb 2026 I’m JJ Strong, a mechanical engineer and third-generation tool designer at Bad Dog Tools, our American-made, family-run company built on durability and innovation. I grew up hauling booths and talking tools at trade shows before I could even drive. Now I design and build and improve our next generation of lifetime-guaranteed tools - our custom induction brazing system to our precision sharpening technology. On weekends, you’ll find me restoring my ’86 Land Rover Defender or ’54 Jaguar XK120 and seeing just how much I can build (or break) with Bad Dog Tools.