Expansion Nuts (#6-32 x 1/2") - 15 pc (3319)
by Paulin
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. Also included in Hillman assortment #3318 / label #259.