one screws are examples of self-tapping screws used in surgery.Place of Origin:Zhejiang, China (Mainland)?Brand Name:ZC ?Standard:DIN 7504Material:Carbon SteelFinish:Blue Zinc Plate?Surface treatment:Heat Treating：?Type: PHILLIPS CSK HEAD?Color:Zinc White?Packing:Carton?Item:China Fastener?Application:Building?Packaging Details:Small box, carton, pallet, nylon bag, for self drilling screwProduct Descripion1. Grade: C1022?2. Size: ST3.5, ST3.9, ST4.2, ST4.8, ST5.5,ST6.33. Length：13-12