Swivel-Blade Deburring Tool: Roth, 1952

Cutting, punching, sawing and grinding leave burrs on the edges of metal, plastic and pressed wood. A knife or file scrapes them off unevenly, and only in skilled hands. Otto W. Roth of Los Angeles patented a swivel-blade cutting tool in 1952, US 2,598,443. A short hooked blade on a shaft turns freely in a sleeve in the handle, bent at less than a right angle. A rounded head at its tip rides on the face of the work and sets the blade's angle, so as the tool is drawn along an edge or round a punched hole the blade follows it and shaves the burr off evenly.