Abstract: An improved tool in the form of a tooth forming rack for cold working a cylindrical workpiece to form teeth thereon to produce, for example, a toothed gear is provided. The rack comprises a plurality of releasable inserts mounted on a tool holder. The inserts are of the throw-away type which enables replacement of only that portion of the rack that is worn or broken, thus extending the ueful life of the entire rack. In a first embodiment the inserts are releasably attached to the tool holder by threaded capscrews. In an alternate embodiment a milled slot within the inserts permits retention by means of tapered retainers attached to the tool holder by threaded capscrews.