The Osborne Plain Grommet Inserting Die #216 sets plain rim grommets and washers. Sizes 00 through 5 and CNC machined from high grade tool steel, while sizes 6 & up are a malleable iron casting. Properly machined and hardened. The finest industrial grommet dies made. For best results use only Osborne grommets and washers with corresponding sizes. Should be set with a rawhide or hickory mallet.