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Hillman Rubber Well Nut (3/8-in-16 x 1-in)

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Well nuts are used to seal bolt holes and prevent leaking
High-strength rubber and steel construction reliably combines corrosion resistance with structural integrity
Upon installation, tightening a machine screw in the brass nut causes the insert to expand, making it secure

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Expansion nuts, or well nuts, consist of a flanged neoprene bushing with a threaded nut embedded in the non-flanged end. As the bolt is screwed into the nut, the rubber on the other side of the hole expands and seals the bolt hole.

Well nuts are used to seal bolt holes and prevent leaking
High-strength rubber and steel construction reliably combines corrosion resistance with structural integrity
Upon installation, tightening a machine screw in the brass nut causes the insert to expand, making it secure
Can be used in either blind or closed-end holes
Parts feature coarse 3/8-in-16 screw thread
Parts measure 1-in deep
5 pieces per retail package