Lincoln 5191 Lincoln Industrial 5191 1/8 In.-28 SAE Taper Thread Grease Fitting, (Blister Pack of 10)

The ball check in the head of the fitting prevents dirt and grit from getting into the bearing. The fittings have a specially formed lip at the fitting base that locks the spring and ball securely in place. Can be wiped clean without forcing foreign material into the fitting and the bearing.