Expansion Nut, Hillman, Rubber/Steel #6-32 x 1 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
• Corrosion-resistant