5/8-18in UNF Grade G Flange Locking Nut Phosphorus Oil

An all-metal, one-piece prevailing torque hex nut with a flange on the bottom side of the nut. With a proof load of 150,000 PSI, this nut reduces inventory (by eliminating a washer) and in-place cost. Designed to be used specifically (but not exclusively) with Grade 8 frame bolts. FNL58FGP