Teeth: 9T-200T Sprockets Type Type A sprockets :Plate (without Hub) Type B sprockets:One side with hub Type C sprockets: Double side with hub Finished bore sprockets:With the inner hole ,keyway and screw Sprockets Size ANSI: 25/35/41/40/50/60/80/100/120/140/160/180/200/240 DIN/ISO:04C/06C/085/08A/10A/12A/16A/20A/24A/28A/32A/36A/40A/48A DIN/ISO:04B/05B/06B/08B/10B/12B/16B/20B/24B/28B/32B/36B/40B/48B Material Alloy Steel, Carbon Steel, Stainless Steel,Aluminum, Copper, Brass Heat Treatment: Hardening and Tempering, High Frequency Quenching, Carburizing Quenching Surface Treatment: Galvanizing/Zinc Plating, chrome plated, Black oxide Treatment Proces: Forging, Hobbing, Precision machining