The spring force produced by its teeth allows the pushnut to create more friction between itself and the shaft increasing its rotational resistance. The black coating on these pushnuts is a zinc phosphate coating with an oil sealer.
Push-On Pushnut, 5/8 Spring Steel, Black, Phosphate & Oil, 2-Piece
For 5/8 stud size.
Push-On Pushnut, 5/8 Spring Steel, Black, Phosphate & Oil, 2-Piece
12 Pack Push-On Push Nuts for 5/8″ Dolly Axle Rods, Spring Steel Wheel Lock Wash
Fastener Type Axle. Thread Size Unthreaded. Material Spring Steel. Material Type Spring Steel. Thread Style Unthreaded. Thread Type Unthreaded. Unit Count 12.0 Count. Thread Class Unthreaded.
10″ Heavy-Duty Replacement Tires, 4.10/3.50-4″ for Gorilla Carts,Hand
100Pcs Flat Washers for Screws, 1/4″ Small Washer, Premium 18-8 (304) Stainless
100Pcs Flat Washers for Screws, 1/4″ Small Washer, Premium 18-8 (304) Stainless
100Pcs Flat Washers for Screws, 1/4″ Small Washer, Premium 18-8 (304) Stainless Steel Washers for Bolts, Anti-Rust, Heavy Duty Washers Set-Industry-Widely Used. Kirphealy washers stand guard at every connection point—dispersing pressure, reducing vibration, and extending service life.

