Hex Head Screw 1)Material:NYLON66 or PC 2)Usage:to fix PCB and main board with good insulation,anti-rust, anti-corrosion Hex Head Screw1) Material:UL approved NYLON66/PC2) Usage:to fix PCB and main board with good insulation, anti-rust,anti-corrosionand light weight.3) Flame Class: 94V-2;4) Working Temp: -20 ~ 120 degree for NYLON66, -20~ 110 degree for PC