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Concave MF Locknuts

When the arched surface contacts the top of the common nut or bearing surface, wrenching flattens the arch, deflecting the nut

Deflects threads from their true helix causing them to firmly grip the bolt threads

The nut takes a permanent set and must be wrenched for further movement

Spins freely with fingers until making contact with the bearing surface

1⁄2 to a full turn with a wrench will lock it securely

Constructed of high quality steel, hot-dip galvanized


Links & PDFs


Catalog Number Description Standard Pack Quantity Carton Weight (Lbs.)
J8581 3/8" Square 3000 61
J8582 1/2" Square 1500 47
J8583 5/8" Square 800 33
J8584 3/4" Square 550 34
J8584-1/2 7/8" Square 400 34

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