1]Material for Twin/Double Screw Barrel:

1)38CrMoAlA       2)SKD61      3)D2               4)38CrMoAl+Ni/Iron/Cobalt based Alloy  

5)4Cr5MoSiV1     6)42CrMo     7)SACM645   8)HPT1,HPT2,HPT3      9)SUS304          

10)316L

2]Technical Parameters:

a.Hardness after hardening and tempering: HB280-320 

b.Nitrided Hardness: HV850-1000

c.Nitrided case depth: 0.50-0.80mm

d.Nitrided brittleness: less than grade 2 

e.Surface roughness: Ra 0.4

f.Screw straightness: 0.015 mm

g.Surface chromium-plating's hardness after nitriding: ≥900HV

h.Chromium-plating depth: 0.025~0.10 mm

i.Alloy Hardness: HRC50-65

j.Alloy depth: 0.8~2.0 mm

PS:Internal thread can be made in feed hole of barrel,usually used in film,pelleting product