1.Common steel:
| Material | 38CrMoAIA | Roughness | Ra0.4 |
| Heat treatment hardness | HB260～320 | Screw straightness | 0.015mm |
| Nitriding hardness | HV950～1000 | Chrome plating hardness | ≥950HV |
| Nitriding depth | 0.5～0.7mm | Chrome thickness | 0.05～0.10mm |
| Fragility | ≤grade 2 | Bimetal depth | 1.0～2.0mm |
| Bimetal hardness | HRC56～65 |
Special steel:
| Hot-worked steel | 1.2344、H13、W360、SKD61 |
| Cold-worked steel | 1.2379、K340、D2、DC53、SKD11、W110 |
| HSS | 1.3343、1.3243、SKH51、SKH55 |
| HIP powder HSS | CPM9V、SK739、SK726、SK742、GH113 |
2.PTA alloy:
Screw flight top use Stellite plasma alloy welding, alloy types:cobalt base,nickel base, iron base alloy.
3.Barrel alloy layer:
Barrel use centrifugal casting alloy inner bore, shrinkagefit technology. Alloy types:cobalt base,nickel base, ironbase alloy.
Specification:
Φ45/2-Φ250/2
L/D Ratio: 18-40
Applications:
PVC pipe, plate, sheet, granulation, wood-plastic extrusion
Inlaid bimetallic layer for the inner hole of the barrel available according to customer requirements
The compression ratio of screws can be designed according to different raw materials.