Alloy classification 
A - iron alloy cylinder                   
B - nickel alloy cylinder  
C - tungsten alloy cylinder

Material of Screw:


Hardness after quenching and tempering:HB260-290



Hardness after nitridation:HV900-1000

Depth of nitrided layer:0.5-0.7mm

Brittleness after nitridation: ≤second level 

Surface roughness:Ra0.4μm


Inside&outside diametre tolerance≤0.02mm

Circular run-out:≤0.04mm

Screw length tolerance:≤0.03mm

Specification Parameter:

Screw Type:

For good plasticizing effect , we have different design of screw barrel to meet customer’s demand .Gradual type, mutant type, wave type, barrier type, double screen type, shunt type, separation type, exhaust type, pin type, mixed type, double- head type, three-head type, multi head type etc.