Chromcraft Polyurethane Soft Tread Replacement Casters - Softer Casters for Wood or Tile Floors (16) These are not your standard casters that come with chromcraft chairs - they are sold seperately if you would like softer casters which are made of softer polyurethane. Standard casters are made of a more rigid hard polyurethane which is not as forgiving on hard wood floors. Available in black only , Will not scratch or scuff floors Dual wheel polyurethane casters are softer than your standard caster Casters rotate full 360 degree for smooth movement Simply pull out old casters and hammer in new ones with rubber hammer or by hand