Product specifications: diameter of parallel double screw (diameter) : 65 - Φ Φ 130 length to diameter ratio (ration of length diameter) : L/D = 16-35 screw compression ratio according to the formula of different products and different design.
Parallel twin-screw technical indicators:
The nitride layer depth: 0.6 to 0.8 mm
Nitriding hardness: 900-1000 hv
Nitride brittleness: level 1 or less
The surface roughness: Ra is 0.4 um
Screw the straightness: 0.015 mm
After nitriding surface chromium plating hardness: p 950 hv
Chromium plating layer thickness: 0.01 0.10 mm
Double metal hardness: HRC55-62
Dual alloy depth: > 2 mm
Otherwise flat double blocks screw piece of supply, strict selection of materials.