1-1/2"-6 Zinc Plated Grade 8 Steel Coarse Thread Lock Nuts (3 pcs.)

Diameter: 1-1/2"
Diameter 2: 2-1/2"
Thickness: 1-5/8"
Material: Steel
Finish: Yellow Zinc
Driver Type: 2-1/4" Wrench
Thread Size: 6 (Coarse)
Hardness: Grade 8
Style: Nylon Insert
Type: Lock Nut

Box of 3.

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