Expansion Nut, Hillman, Rubber/Steel 5/16 in -18 x 3/4 in

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.

• Used to seal bolt holes to prevent leaking
• Can be used in blind and closed-end holes
• Made of high-strength rubber and steel parts
• Resistance to corrosion