3/4"-10 Black Phosphate Grade 2 Steel Coarse Thread Nylon Insert Lock Nuts

Diameter: 3/4"
Diameter 2: 1-7/32"
Thickness: 57/64"
Material: Steel
Finish: Black Phosphate
Driver Type: 1-1/8" Wrench
Thread Size: 10 (Coarse)
Hardness: Grade 2
Style: Nylon Insert
Type: Lock Nut

Box of 42.

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