15mm-250mm screw diameter
300mm-8000mm screw length
40mm-400mm barrel outer diameter
L/D：10-46
screw:
1. normal nitriding screw (SACM645)
2. top gear spray-welding bimetallic screw
3. wlfram steel screw
4. hard scries screw:NPT1,NPT2,NOT3
5. ceramic and diamond on surface screw
barrel
1. normal nitriding barrel (SACM645)
2. centrifugal casting bimetallic barrel(分ABC三等及)
3. hard series barrel（NPT1，NPT2NPT3）
HV≥290 surface hardness
HV850-1000 nitriding hardness
0.45-0.7mm nitriding depth
≤一级 nitriding brittleness
0.015mm screw strightness
≥900HV chrome hardness
0.05-0.1mm chrome thickness
60-70 bimetallic hardness
0.8-2.0mm bimetallic depth
