Curv-O-Mark® multi trammel heads help pipe fitters, welders, and fabricators accurately mark circles, arcs, and layouts for fabrication and fit-up work. Designed for use with standard 1/2" pipe as a trammel bar, they provide precise, repeatable marking performance for a wide range of layout applications. Works with standard 1/2" pipe as a trammel bar to create circles and layouts in a wide range of sizes Radius set points cast into the heads allow quick, accurate layout setup for improved productivity Case-hardened center point and hardened steel scribe deliver precise, repeatable marking performance Marks circles from 1-1/2" diameter and larger depending on the trammel bar length used Includes Allen wrench, soapstone, scribe, and pointer to help get layout jobs started right away