1/2"-13 Zinc Plated Grade 8 Steel Coarse Thread Nylon Insert Lock Nuts

Diameter: 1/2"
Diameter 2: 27/32"
Thickness: 39/64"
Material: Steel
Finish: Yellow Zinc
Driver Type: 3/4" Wrench
Thread Size: 13 (Coarse)
Hardness: Grade 8
Style: Nylon Insert
Type: Lock Nut

Box of 6.

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