Bicycle steel balls are mostly in place of bearing steel balls where expected wear and tear is less. They are produced using extremely sophisticated and specialized machines. Heat treatment is one of the most critical operations which gives required strength & hardness. It makes the balls tough and wear resistant. Apart from intermediate vigil at all operations, for all quality parameters, finished products are also tested with extremely sophisticated equipments to ensure right quality of balls.
Mainly four sizes are used for bicycles & its spares like Hub, Pedal, Freewheel, Handle, etc. These are:- 1/4", 3/16", 5/32", 1/8".
Material & Grade

Material	C	Si	Mn	P	S	Cr	Grade
AISI 52100/EN 31	0.95 to 1.10	0.10 to 0.35	0.40 to 0.70	0.035 max	0.40	1.20 to 1.60	200/500
AISI 1060	0.50 to 0.60	0.10 to 0.35	0.50 to 0.90	0.041 max	0.40	-	500
AISI 1012	0.10 to 0.15	-	0.30 to 0.60	0.045 max	0.045	-	500