Product instruction：Professional producer of screws from year 2007 ,Website: , main have self-drill screw , drywall screw , wood screw , slef tapping screw , machine screw , chipboard screw . Variety of complete kinds , reliable quality , compeitive price  . Welcome to enquiry more info ! Place of Origin:Zhejiang, China (Mainland)Brand Name:ZCStandard:DIN 7504KMaterial:Carbon SteelFinish:Blue Zinc PlateSurface treatment:Heat TreatingType: HEX WASHER HEADColor:Zinc WhitePacking:CartonItem:China FastenerApplication:BuildingPackaging Details:Small box, carton, pallet, nylon bag, for self drilling screwProduct Description1. Grade: C10222. Size: ST3.5, ST3.9,ST4.2,ST4.8, ST5.5,ST6.33. Length：13-120mm4. Standard: DIN 5. Certification: ISO9001, CEProduct Name:Self drilling screwMaterial: Carbon steelUsed:building industry machinery