Castle or round made of mild steel. AX1-1/4 uses MS24665-377 cotter pin, AX1-1/2 uses MS24665- 364. SPACERS: For use with 500×5 or AX5 axles, 2 ea #A484 required per axle for Cleveland. Cleveland kits CWB199-153 & CWB199-156 require one7/16″ spacer and one 1/4″ spacer per axle.