Weld Nut

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Weld Nuts are a six-sided, internally threaded fastener with three triangular weldable projections on the top surface of every corner of the fastener. 

Weld Nuts are designed to achieve two things: (1) the pilot is self-locating so it can be used with an automated feeding mechanism: (2) when the nut is fully tightened, the pilot protects the internal threads from welding residue.