3.Full-Harded screw ( Material: SKH55,DAC, SKH9 etc.)全硬系列螺杆
Suitable for less than 25%-65% glass fiber material
适用范围：用于原料含25%-65%以下玻纤
4.Super antifraying coated screw 超耐磨涂层螺杆 （Material:THP series materials）
Coated hardness（涂层硬度）: ≥HV2000
Coated thickness（涂层厚度） 0.05-0.06mm
The service life of all hard and coated screw is increased by more than 2 times.
Full-Harded screw & Super antifraying coated screw with2 times longer using life than general (Nitrided) screw .
全硬系列及涂层螺杆使用寿命比原来增加2倍以上
