Patent ID: 8800844

Claim:
An apparatus configured to reinforce a friction plug weld in a workpiece, the apparatus comprising: a chuck configured to rotate a plug and to force the plug through a hole through the workpiece, the hole comprising a first width on a root side of the workpiece and a second width on a face side of the workpiece; the plug configured to: forge weld to the workpiece, and plastically deform to comprise: a weld land surrounding a root side end of the plug, and a coin surrounding the weld land; and an anvil adapted to be placed against a root side of the workpiece, the anvil comprising: a first cavity configured to receive a tip of the plug, the first cavity being further from the workpiece than a second cavity and a third cavity; the second cavity configured to substantially surround the first cavity and extrude a first plasticized portion of the plug to form the weld land, the second cavity comprising a width and a depth that are larger and smaller respectively relative to the first cavity, the width of the second cavity being greater than the first width of the hole; and the third cavity configured to extend outward around the second cavity and extrude a second plasticized portion of the plug to form the coin, such that the third cavity comprises a height that is less than a width of the third cavity.