5/8"-11 Black Chrome Nylon Insert Lock Nuts (3 pcs.)

Diameter: 5/8"
Diameter 2: 1-1/16"
Thickness: 3/4"
Material: Steel
Finish: Black Chrome
Driver Type: 15/16" Wrench
Thread Size: 11 (Coarse)
Style: Nylon Insert
Type: Lock Nut

Box of 3.

A lock nut is a nut that resists loosening under vibrations and torque.