T-Dollies are used in.onin. or in.offin. dolly, on the car, or bolted to your workbench to form tight radius bends in trim, body panel style lines, rounding panel edges and more in steel aluminum, copper, brass etc. Machined from 4140 and TIG welded to the mounting post. Polished working surfaces. This set includes four T-Dollies with 6in. long working face, in the following diameters: 1/2in., 3/4in., 1in., and 1-1/4in..