... :special alloy steel 2.Good customer service ... 2.0mmScrew type:Gradual type, mutant type, wave type, barrier type, double screen type, shunt type, separation type, exhaust type, pin type, mixed type, double- head type, three-head type, multi head type ... etc.scope of application : PVCwood-plastic., PE wood-plastic,,Super high polymer board,1/2 ...