Product instruction：A self-tapping screw is a screw that can tap its own hole as it is driven into it. For hard substrates such asmetal or hard plastics,Website:http://www.nbzhencheng.com, the self tapping ability is often created by cutting a gap in the continuity of the thread on the screw, generating a flute and cutting edge similar to those on a tap. Thus, whereas a regularmachine screw cannot tap its own hole in a metal substrate, a self-tapping one can (within reasonable limitsof substrate hardness and depth). For softer substrates such as wood or soft plastics, the self-tapping ability can come simply from a tip that tapers to a gimlet point (in which no flute is needed). Like the tip of a nailor gimlet, such a point forms the hole by displacement of the surrounding material rather than any chip-forming drilling/cutting/evacuating action.Some self-tapping screws are also self-drilling, which means that, in addition to the tap-like flute in the leading threads, there is also a preliminary drill-like fluted tip that looks much like the tip of a center drill. These screws combine a thrilling-like action and thefastener installation itself into only one driving motion (instead of separate drilling, tapping, and installingmotions); they are thus very efficient in a variety of hard-substrate applications, from assembly lines to roofing.Self tapping screws are used in a variety of applications ranging from DIY carpentry to surgery. Many dental implants and orthopedic bone 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 Description1. Grade: C1022 2. 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 screw Material: Carbon steelUsed:building industry machinery
