摘要 |
A preassembled domed washer and fastener that can be snapped together after thread rolling and heat treatment. The inner periphery of the washer is reduced in thickness to provide flexibility and the fastener is provided with an interrupted annular ledge. The flexibility of the washer's inner periphery permits it to yield as it is pushed over the ledge and to snap back into engagement. The knurling or other interrupting of the ledge insures that large slivers from the case hardened fastener which cause handling problems and may reduce the amount of interference to the point the washer can fall off, are not formed. |