Reliable HNLNS51618MR Lock Nut, 5/16-18 Thread, Stainless Steel, 18-8 Grade

Reliable Lock Nut, Thread Size: 5/16-18, Hex Size: 0.502 in W Flat x 0.557 in W Corner, Stainless Steel, 18-8 Grade, Dimensions: 0.359 in H