1/4"-28 Zinc Plated Grade 2 Steel Fine Thread Kep Lock Nuts

Diameter: 1/4"
Diameter 2: 1/2"
Thickness: 3/16"
Material: Steel
Finish: Zinc
Driver Type: 7/16" Wrench
Thread Size: 28 (Fine)
Hardness: Grade 2
Style: Kep
Type: Lock Nut
Washer Diameter: 1/2"

Box of 15.

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