The screw ratio (L/D) is bigger, plastic ability is stronger, the temperature distribution is even Performance and Characteristics:1. The screw uses the most advanced alloy treated technique and precision finishing, which hardness is higher, the corrosion ability is better, the life is 2 and 3 times longer than the screw by nitrided.2. The screw ratio (L/D) is bigger, plastic ability is stronger, ...