Self Drilling Screws are used to fasten together steel or other metals and are typically used to join materials like sheet metal. The unique point or flute acts as the drill bit for the screw, effectively combining the screw with its drill bit. Since the self drillers drill their holes while creating reusable threads, they virtually eliminate the need to drill a pilot hole, tap it, and then install the screw. With these screws, you can do it all in one operation. Not having to pre-drill holes saves both time and effort.There is some confusion regarding self drill screws and self-tapping screws. Every self-drilling screw is a self-tapping screw but with the added feature of a drill point instead of a sheet metal screw point such as an AB sharp point. If a screw will drill its hole, it is generally a self-drilling screw.The TEK number of the tip distinguishes these screws. Generally speaking, this number has to do with the drill point's length at each screw's end and, by extension, the material thickness which the screw can reliably penetrate. The most common TEK Screw point is a TEK 3. Thinner metals such as 12 gauge steel are what most self-drilling screws are for, but they can pierce 20 to 14 gauge metals. We recommend a TEK 5 point for 14 gauge metals and below. So long as the unthreaded portion of the TEK point (pilot section) can completely drill through the material before the threads engage, you'll minimize the chance of the fastener binding and breaking.For the self-drilling action of self drillers to work, they are made of a material that is harder than the material you are drilling. The most common material used in these Screws is 410 Stainless Steel. This grade of stainless will provide the corrosion and rust resistance of standard 18-8 stainless. However, it has been heat-treated (up to 40 Rockwell C) to ensure that the drill point will successfully pierce a given application's metal.We are DD Fasteners, the whole line of products are produced by the factory, strictly control the quality standards, and have obtained international certification, ISO9001, ANAB, SGS certification, to provide customers with safe, stable and efficient products, if you have any inquiries, please feel free to contact us.

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