... big chain sprocket 1.meterial 45 steel, Cr, Mn, Heigh carton steel, or carton steel or plastic.2. we do ... it according your required.3. HRC 35 TO 65 , forging , cast ,CNC4. we recived a small order or big order ... . could you tell me your require, we will best do it.5. if ... according to your require, offer at once, braking big chain sprocket