|L/D||L/D=15-46||Chromium plating thickness||0.05~0.10mm|
|Surface roughness||Ra 0.4μm||Hardness of chrome plating||HV＞850|
|Nitride brittleness||First grade||Alloy layer depth||1.2~2.5mm|
|Nitriding depth||0.5～0.8mm||Hardness of alloy layer||HRC＞65|
There are ordinary type, gradual change type, mutation type, barrier type, pin type, DIS open wind flow type, exhaust type, BM type and separation type screw. The compression ratio can be manufactured according to clients’requirements, the number of screw heads can be single head or multiple heads, and the barrel can be slotted strong feeding system split type, etc., and can be designed for clients.