These Forgefix Through Bolts (also known as Wedge Anchors or Toothless Anchors) have a Zinc Yellow Passivated finish for durability and corrosion resistance. They are through-fixing, and extremely economical and quick to install. APPLICATIONIdeal for fixing brackets, cladding, restraints, racking, fabricated stairwells and industrial doors.Ensure the correct socket drive or spanner is used to ensure accurate installation. The Zinc Yellow Passivation process of electroplating is similar to the Galvanised and Zinc Plated processes but with the addition of a yellow dye. It provides a coating that is aesthetically pleasing, and which offers excellent resistance to corrosion.Through Bolt Zinc Yellow Passivated M20 x 220 Bag 5 Material: Metal.