... :SEMS SCREW 4. ISO9001:ISO14 Features:Stainless steel wing screws with plastic head A. Screw Prosduct detail 1)MaterialCarbon Steel of grade ... , black zinc, colour zinc, blue zinc), chromated,nickel plating,dacromet and etc.3)Normal sizeM2-M244)Normal Length10mm to 120 mm5 ... ’ complaint. We have the responsible QC, Engineers and after sale worker to deal with such things.In case this thing happened, we ...