News Center
Shanghai SMG Intelligent Technology Co., Ltd.
What are the installation requirements for high-tensile bolts in steel connections?
Release time:
Jul 29,2024
The requirements before the installation of high strength bolts are:
① Before the steel structure is assembled, the flying edges, burrs, welding spatters, etc. should be removed. The friction surface should be kept dry and neat, and should not be operated in the rain.
② High-strength bolts connecting vice should be stored separately according to the batch number, and should be used in the same batch. In the storage, transportation, construction process shall not be mixed, to prevent corrosion, staining and bruising of the threads may lead to changes in the torque coefficient.
③ Selected high-strength bolt form, specifications should meet the design requirements. Before construction, high strength large hexagonal head bolts connecting vice should be factory lot number retest torque coefficient; torsion shear high strength bolts connecting vice should be factory lot number retest pre-tension, after passing the retest before use.
④ The test results of anti-slip coefficient of connecting surface of high-strength bolts should be in accordance with the design requirements, and the connecting surface of the components should be in accordance with the surface condition of connecting surface of the test pieces.
(2) The installation methods of high-strength bolts are:
① high strength bolt joints should be connected by punching nails and temporary bolts, the number of temporary bolts should be 1/3 of the total number of bolts on the joints and not less than two, the number of punching nails used should not exceed 30% of the number of temporary bolts. Installation of the nail shall not be forced to hit the screw hole deformation caused by flying edge. It is strictly prohibited to use high-strength bolts instead of temporary bolts to prevent damage to the threads caused by the torque coefficient increases.
Misaligned bolt holes should be reamer or coarse file to deal with regularization, processing should be the first to tighten the temporary bolts between the main plate to the iteration of the gap, in order to prevent chips fall in. The bolt holes shall not be reamed by gas cutting.
The steel structure shall be mounted in the temporary bolt connection state for accuracy correction.
② High-strength bolts can be installed after the steel structure installation accuracy adjustment reaches the calibration regulations. Firstly, install the screw holes in the joints where temporary bolts and punches are not installed, and the bolts should be able to penetrate into the screw holes of the bolts and punches vertically, and the direction of penetration should be the same. Each bolt shall not have 2 or more washers at one end, and large nuts shall not be used in place of washers.
After these mounted high-strength bolts are sufficiently tightened with an ordinary wrench, the punch nails and temporary bolts are replaced with high-strength bolts one by one.
In the process of installation, the surface of the connecting vice if coated with excessive lubricant or rust inhibitor should use a clean cloth to gently wipe off the excess grease, to prevent it from flowing into the connecting surface after installation, shall not be cleaned with detergent, otherwise it will cause changes in torque coefficient.
WhatsApp/WeChat/Tel：
E-mail：
