Fuller (Metalworking)

In metalworking, a fuller is a tool used to shape hot metal, with a rounded nose, cylindrical or parabolic, mounted on a handle as an upper fuller or a shank as a lower fuller; the lower fuller's shank fits into the hardy hole of the anvil. Set against the metal stock and struck with a hammer, the fuller's rounded nose spreads metal more efficiently than a hammer's flat face, leaving ridges that are later flattened; the general term fullering covers any forging process that creates a sharp transition in the stock's cross-section, and with care some fullering can be done with only a hammer and the anvil's own edge acting as the fuller.