7/8"-9 Black Phosphate Grade 2 Steel Coarse Thread Lock Nuts (29 pcs.)

Diameter: 7/8"
Diameter 2: 1-15/32"
Thickness: 3/4"
Material: Steel
Finish: Black Phosphate
Driver Type: 1-5/16" Wrench
Thread Size: 9 (Coarse)
Hardness: Grade 2
Style: Top Lock|Type C
Type: Lock Nut

Box of 29.

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