3/4"-16 Zinc Grade 2 Nylon Thin Lock Nuts (5 pcs.)

Diameter: 3/4"
Diameter 2: 1-7/32"
Thickness: 27/64"
Material: Steel
Finish: Zinc
Driver Type: 1-1/8" Wrench
Thread Size: 16 (Fine)
Hardness: Grade 2
Style: Thin Pattern Nylon Insert
Type: Lock Nut

Box of 5.

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