Material:38CrMoAIA
Tempering hardness: HV260-280
Diameter:¦µ15mm-¦µ300mm
L/D:4-35
Nitrided Hardness: HV900-1000
Depth of nitriding: 0.5mm-0.7mm
Nitriding brittleness: ¨Q 2 grade
Surface roughness:Ra 0.4um
Straightness of the screw/barrel:0.015mm/m
Inside&outside diameter tolerance:¨Q0.02mm
Circular run-out:¨Q0.04mm
Screw length tolerance:¨Q0.03mm
Key&spine tolerance grade:Grade 7