Grade-A superhard and high wearing resistance bimetallic screw: the base material is imported Sweden Km22  steel and superhard high speed steel, which is  high wearing resistance, high toughness and high corrosion resistance, hardness could reach HRC59-64, allying for processing nylon plus 50% ~ 60% glass fiber, bakelite, magnetic powder, ceramic powder, magnesium powder, iron powder, copper powder, aluminum and other special plastic, the service life of 5-8 times longer than the nitrided one.

    Grade B strong corrosion resistantance bimetallic screw:take base material of  improted GRC-276, GE113 ,which is strong temperature resistance and high corrosion resistance, applying for the special plastic which is high speed,high temperature and high wearing and corrosion, nylon plus 20% - 40% fiber glass, halogen-free flame retardant plastic, PPE flame retardant plastic, XPS flame retardant plastic special plastics through solid solution plus aging hardening,  the service life of 4-6 times longer than the nitrided one.

    Grade-C wearing resistance bimetallic screw: take base material of 38 CrMoAla, SKD61, din 1.8550 and1.8519 ,screw flight and bottom cladding alloy powder, the surface hardness can be reach HRC60 ~ 62, the thichkness of alloy layer is 1 mm - 2.5 mm, with extremely high wear resistance and corrosion resistance, applicable to PC, PE, PVC and other plastic processing.

bimetallic screw for PC only:take base material of special stainless steel, 42 CrMo, then hardening and chroming ,suitable for processing transparent plastic products, such as lens, white material, back plate, guide plate, acrylic products, the service life is 3-5 times longer than the nitrided one .