A self-tapping screw with a press washer is a screw that looks like a small squeezed washer from above. It is used in many areas of industry and construction. Moreover, some say that this invention has no analogues in terms of advantages. What is the difference between a self-tapping screw and a press washer? Let's find out.
Varieties
Today, there are two main types of such instruments:
- Sharp devices.
- With a drill.
To find out the features of each of them, let's look at both types separately.
Sharp metal screws with press washer
The main material from which they are made is high-strength carbon steel. Moreover, during the production process, a small layer of zinc is applied to this tool, which protects it from rust and other negative environmental influences. Thus, this self-tapping screw with a press washer is very hardy, reliable and resistant in terms of corrosion. The head (that is, the cap) of this tool has a hemispherical shape, under which there is a welded press washer. The spitz of such a self-tapping screw is most often cruciform.
Where is the self-tapping hemisphere "press washer" used? Its main area of application is the installation of wooden structures and work with various wood materials. Due to the presence of a press washer, the device perfectly presses the sheet material to the surface to be treated, thereby ensuring a reliable and high-quality connection. The result is a strong and durable construction. And even from an aesthetic point of view, it looks very attractive. That is why a sharp self-tapping screw with a press washer is the leader among its "brothers".
Drill Devices
They are usually made from higher quality steel and are also coated with a thin layer of zinc. The head of this device has a hemispherical shape, and the press washer is placed on its back side. And if the design of this tool may have some similarities with the first, then with the scope it is quite the opposite. The main feature that distinguishes this self-tapping screw with a press washer from others is the ability to work exclusively with a metal surface. The tip of the device, which resembles the shape of a drill, quickly makes a hole in the steel sheet, and the thread goes further into this material. Thus, self-tapping screws for metal with a press washer provide not only a high-quality connection, but also significantly reduce the time for performing certain work. It is not at all necessary to use a drill in this case: if the width of the hole being made is less than 2 millimeters, the self-tapping screw itself can handle this work. Well, if there is already a preliminary hole in the metal sheet, the self-tapping screw will independently cope with the necessary task without the help of any other devices.
Price
Like all other tools of this type, these devices are usually purchased in bulk. The approximate price for 1 kilogram of such self-tapping screws is from 100 to 150 rubles.
