... , multi-format support, high reliability, long life. 1, structure type Lift divided by structure type: Type 1 - same as the screw ... ), II (flange type), III (screw-type), IV (flat head type) four types. 2 types of screw head structure isdivided into: I ... isnormal (P) and slow (M). 5, the protective screw screw lift the protective type 1 is divided into: basic, anti-rotationtype ...