1. Self-drilling screws for the building and construction industries. For those application fixig to steel, timber and plasterboard to steel.
2. Self-drilling screws intended for drilling and tapping into layered or unlayered steel with a minimum total thickness of 0.9mm shall be type ASD, BSD or CSD.
3. Type ASD and BSD screw have spaced threads and type CSD screws have threads of UNC machine screw diameter-pitch combination with a 60 degree basic thread form.
The drill points for ASD, BSD and CSD shall be No.2, No.3 and No.4 designed to accommodate different panel thicknesses. IFI standard: There are Type BSD and Type CSD screw types shall conform to those specified for type b and type c tapping screws, respectively. As specified in ASME B18.6.4 or SAE J478. 1. Din7504 k: ind. Hex waher head. 2. Din7504 p: phil flat head. 3. Din7504 n: phil pan head. 4. Ind. Hex flange head. 5. Phil wafer head / modi truss head. 6. Phil thin wafer head.