7/16"-20 Polished 18-8 Stainless Nylon Insert Lock Nuts (4 pcs.)

Diameter: 7/16"
Diameter 2: 23/32"
Thickness: 15/32"
Material: Stainless Steel
Finish: Polished
Driver Type: 5/8" Wrench
Thread Size: 20 (Fine)
Hardness: 18-8
Style: Nylon Insert
Type: Lock Nut

Box of 4.

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