Bolts or screws in connection, it is necessary to pay attention to some of its basic characteristics, and then according to the different uses and performance of the bolts to conduct standard operation.This article mainly to analyze the bolt in the connection of some basic knowledge and essentials.

Our daily use of internal and external hexagon bolts belong to the connection of ordinary bolts, it is completely according to the requirements of construction performance to choose bolts of different materials to install.

For this type of common bolt, the minimum tension test of the bolt can be carried out before installation. As long as the bolt meets the current national standard, it can be safely used.

After the installation of this common bolt, the thread at the end of the two rings should be exposed, which is the most reliable connection length and tension pretension state, suitable for industrial field of equipment installation and small electrical assembly.

Recheck the torque of bolts

Steel bolt torque review is very important for the test methods and standards, industry association published professional testing process, it is divided into two torque detection and corner detection, based on a formula to calculate the correct torque value, and then use the professional test reference, torque wrench is too tight to loose a bit, too loose should tighten a little bit, in principle is to ensure that each measuring torque of bolt preload value is the same.

We draw a line between the end of the bolt and the vertical corresponding position of the nut, and then add the nut back to 60 degrees, and then screw the nut back to the original position with the torque wrench. This is a simple process of torque recheck.

The acceptable deviation in this process is less than 10%, and it can be regarded as qualified.Because the plane of the steel plate is not absolutely flat, after the bolt is tightened, the connection between the head and the steel plate will be uneven, so the torque value of each bolt is allowed to have a tolerance range.The corner detection method is similar.

Installation process of steel structure bolts

Different from ordinary bolts, steel structure bolts are divided into the process of one straight screw, the first rotation and the second tightening in the installation process.

The primary tightening and secondary tightening of bolts are not invalid operations, but in the process of repeated tightening, the bolt head and steel plate can be better fitted, and this process can also make the bolt force more uniform.

For exposed threads, as with common bolts, two turns of thread are preferred.When the bolt passes through the hole of the steel plate, we cannot use the method of gas welding and burning cutting, because the holes burned in this way are uneven in size and have too many burrs around them.

During the installation process, the load-bearing torsion of the effective cross-sectional area of the bolt will be affected.