#10-32 Chrome Plated Steel Fine Thread Nylon Insert Lock Nuts (10 pcs.)

Diameter: #10
Diameter 2: 7/16"
Thickness: 1/4"
Material: Steel
Finish: Chrome
Driver Type: 5/16" Wrench
Thread Size: 32 (Fine)
Style: Nylon Insert
Type: Lock Nut

Box of 10.

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