304 stainless steel flange face external hexagon screw m8-m12 hexagon flange bol

Self tapping screw Generally speaking, it refers to the wood Du screws with sharp points, coarse teeth and hard texture. There are also aluminum alloy and plastic ones. A special type of self tapping screw for tapping metal holes is called a tap. Self tapping screws are used for non-metallic or soft metals, without backing holes and tapping; self tapping screws are pointed in order to "self tap"; ordinary screws are flat headed, with the same thickness. Self tapping screw means that the hole drilled is a hole without tapping. The screw used is different from the general one. The head is pointed, and the pitch is relatively large. It is similar to the non chip tapping. It can be directly screwed in without tapping. Metal and plastic usually use this method. It can "drill, squeeze and press" the consolidated body into corresponding threads by means of its own thread on the consolidated material to make it closely cooperate with each other. Self tapping screw is a kind of screw with drill bit, which is constructed by special electric tools, drilling, tapping, fixing and locking Self tapping screw Do it in one go. The self tapping screw is mainly used for the connection and fixation of some thin pieces, such as the connection between color steel plate and color steel plate, the connection between color steel plate and purlin, wall beam, etc., and its penetration capacity is generally no more than 6 mm and no more than 12 mm. The self tapping screw is often exposed to the outside, and has strong corrosion resistance; its rubber seal ring can ensure that the screw does not leak water and has good corrosion resistance. Self tapping screw is usually described by screw diameter series, thread number per inch and screw length. There are 10 and 12 stages of screw diameter series, and the corresponding screw diameters are 4.87mm and 5.43mm respectively; the number of threads per inch is 14, 16 and 24. The more threads per inch, the stronger the self drilling ability