... gram plastic injection machines, 15-300mm single screw extruders, 30-130mm tapered and parallel double screw extruders, rubber machinery, ... the treatment of structural improvement, nitriding, grinding, and polishing. The company can make the screw cylinder ... frequency quenchingSpray coating Bimetallic-alloyVacuum quenching Standards of single screw and cylinder of extruder machine:φ20mm~φ300mm ratio ...