Service HotlineWhen installing the ventilation duct, because the gap between the air duct and the wall and between the air duct and the air duct is deep and narrow, the arm cannot enter into it to operate, which brings about the installation of the screws and nuts at these positions. The following three methods are generally used: one is to directly break the wall for installation, but this method damages the building greatly, and cannot be used for the installation of screws and nuts in the gap between the air ducts; the other is to Set the inner flange in the air duct and connect it with bolts, which will reduce the effective cross-sectional area of the air duct and increase the resistance of the gas flow. Moreover, people need to enter the air duct for construction during installation. Considering the size of the air duct First, the supporting firmware with a high position and no force has certain hidden dangers; third, it is directly ignored and not done, but it is easy to cause the air duct connection is not tight and the air volume loss is large. The above-mentioned methods all have major construction defects, which not only waste a lot of manpower and time in the construction process, but also have the problem of low air supply efficiency.
The inch thread is the thread size marked in inch. According to the shape, it is divided into two types: cylindrical and conical; according to the tooth angle, it is divided into two types: 55° and 60°. The 1/4, 1/2, 1/8 marks in the thread refer to the diameter of the thread size in inches. One inch equals 8 cents, 1/4 inch equals 2 cents, and so on.
There are two typical pin shearing fixture tooling, among which the traditional fixture shown in Fig. 1 is more complicated and consists of fixture, spacer, washer and shearing block guide post, hardened bushing, shearing block and so on. The cylindrical pin is installed in the hardened bushing, and the axial load is applied through the shear block to complete the shear test. The fixture is complicated in manufacture and has many consumables, because the size of the hardened bushing is similar to that of the cylindrical pin. , and to keep the notch of the cylindrical pin upward, it is difficult to install before the test, and the broken cylindrical pin after the test remains in the hardened bushing and is difficult to remove.
Screw name broadcast 1. Machine screw 2. Self-tapping screw 3. Drilling screw 4. Wallboard screw 5. Fiberboard screw 6. Wood screw 7. Hexagonal wood screw 8. Non-prolapse screw 9. Combination screw 10. Micro screw 11. Furniture screws 12. Electronic screws
Metric threads are measured in MM (millimeters) and have a cusp angle of 60 degrees. Both US and Imperial threads are measured in inches. The cusp angle of the American thread is also 60 degrees, while the cusp angle of the imperial thread is 55 degrees. Due to the different units of measurement, the representation methods of various threads are also different. For example, M16-2X60 represents a metric thread. His specific meaning is that the nominal diameter of the screw is 16MM, the pitch is 2MM, and the length is 60MM. Another example: 1/4—20X3/4 means the inch thread, what he specifically means is the nominal diameter of the screw It is 1/4 inch (one inch = 25.4MM), there are 20 teeth on one inch, and the length is 3/4 inch. In addition, if you want to express American screws, UNC and UNF are usually added to the back of the British screws to distinguish between American coarse teeth or American fine teeth. In the usual domestic sales business, the most common standards we encounter are GB (National Standard) and DIN (German Standard). In the production of Yaoda, the following standards are mainly encountered: GB30; GB5783; GB5782; GB52; GB6170; GB818; GB819; GB845; GB846; GB70; DIN912; DIN933; It has been replaced by GB5783 (new national standard). GB52 (old national standard) has been replaced by GB6170 (new national standard) in the standard book.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: cap screw caps, color aluminum alloy lock nuts, American standard British and American spring meson washers, spacer studs and other products, we can provide You have the right fastener solution for you.
