1.50-16 AXLE NUT with closed end for wheel pant support. Closed end has 3/8-16 threaded hole that is 0.50 deep to allow bolt with jam nut to be used to support wheel pant. Axle bore is 0.85 inches deep. Nut has slots for cotter pin restraint. The WHLAN6L is gold anodized 6061-T6 Aluminum.