Product Code DIN603
A Mushroom Head Square Neck Bolt, also known as a Coach Bolt, Cup Square or Carriage Bolt, has a square shoulder under a rounded head which resists turning when the nut is tightened or removed.
Carriage bolts are pushed into a hole the same size as the shank and then hammered in the rest of the way, where the square shoulder locks it firmly in place. Used whenever a smooth finish surface is needed so that nothing becomes snagged on the fastener.
Zinc plating, retards the corrosion rate in a normal atmosphere.