5/8"-11 Heavy Hex Lock Nut, Zinc Plated Finish, Grade 8 Steel, Right Hand, PK50

Disc-Lock™ locking nuts get tighter under shock and vibration—forces that cause other locknuts to come loose. The proprietary design is great for high-stress, vibration-sensitive areas and in safety-critical applications. Interlocking cams form the free-spinning, 1-pc. locking nut assembly. The top threaded hexagon nut has cams underneath and a pilot that retains the washer. The bottom hex flange washer has a smooth bearing surface and cams on top. Under vibration and shock, the cams try to rise against each other, locking the assembly to maintain the bolted clamp load and protect joint integrity. Easily installed and removed with standard equipment—they're reusable. Can be used with Grade 5 (Class 8.8), grade 8 (Class 10.9), and stronger bolts.