... : carbon steel Size: M2.9-M6.35 Finish: zinc, nikel, cr, black Self drilling tapping screws StandardsISO, DIN, AS/NZS, GB, ANSI , BS ... .9-ST8,or as request Types of head hex head,hex flange head,oval,countersunk head,flat headGrade 4.8 8.8 10.9 ... problems, please contact with us at onceSurface treatmentBlack oxide, zinc-plated, black chromium,nickel plated,passivation.HDG,Packinggeneral export packing ...