... to match with screw extruder. It is designed according to the specification in code ZBJ19009-88, featured with high-strength ... alloy steels for gear wheel and shaft parts. The gear is treated with carburation, quenching and gear grinding. ... 12.5 -- (,)ZLYJ series 133, 146, 173, 200, 225, 250, 280, 315, 330 are available. extruder gearbox of ZLYJ series for plastic extrusion machine