Osborne No. 217 Sets rolled rim grommets & spur washers. Sizes 0 thru 5 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 G2, N2 & B2 with corresponding sizes.