Steel structure bolts are commonly used connectors in engineering and are widely applied in steel structure projects. They are mainly used to connect the joint parts of steel structure steel plates, achieving excellent fastening effect. Steel structure bolts have high strength and belong to the category of standard parts. Different types of steel structure bolts have different classification standards and construction methods, which are explained in detail below for reference by relevant personnel.
I. Application of Steel Structure Bolts
Steel structure bolts are high-strength bolts, widely used in various types of steel structure projects. In steel structure connections, the fastening performance of bolts directly affects the stability and safety of the engineering structure, so high performance requirements are put forward for them. Under normal circumstances, steel structure projects need to select bolts with a strength grade of 8.8 or above, and the commonly used grades also include 10.9 and 12.9. For steel structure bolts that do not require electroplating treatment, natural color materials (i.e., the natural color of the base material without surface treatment) can be selected when purchasing.
For non-professionals (laymen), it is necessary to understand the relevant knowledge in advance before using steel structure bolts to avoid selecting the wrong products and affecting the construction quality. Therefore, it is particularly important to master the classification and construction methods of steel structure bolts.
II. Classification of Steel Structure Bolts
High-strength steel structure bolts are mainly divided into two types: torsion-shear type high-strength bolts and large hexagon head high-strength bolts, each with its own characteristics in structure, performance and construction method.
① Large Hexagon Head High-Strength Bolts
Large hexagon head high-strength bolts are high-strength upgraded versions of ordinary bolts. Adopting a large hexagon head design, they have simple structure, strong versatility, high fastening performance and bearing capacity, and are suitable for various steel structure joint connections.
② Torsion-Shear Type High-Strength Bolts
Torsion-shear type high-strength bolts are optimized and improved on the basis of large hexagon head high-strength bolts. Their appearance is "T" shaped (the head is hexagonal, and the tail is equipped with a torsion-shear groove), and the construction performance is more superior. During construction, the upper and lower sections of the bolt can be directly locked by a torsion-shear electric wrench. Its special structural design can effectively reduce the risk of bolt fracture during construction, and the fastening torque is uniform, with higher construction efficiency.
III. Construction Methods of Steel Structure Bolts
The construction of steel structure bolts must strictly follow two core steps: "initial tightening" and "final tightening". Both steps are indispensable, and standardized operation is required to ensure the fastening quality.
① Initial Tightening
When initially tightening steel structure bolts, impact electric wrenches or torque-adjustable electric wrenches can be selected. When using electric wrenches to install bolts, the torque must be controlled in strict accordance with the design standards and bolt strength grades to avoid excessive or insufficient torque, which will affect the fastening effect and service life of the bolts.
② Final Tightening
In the final tightening link of steel structure bolts, corresponding special tools must be used according to the bolt type, and the construction requirements are different:
- For torsion-shear type steel structure bolts, a torsion-shear electric wrench must be used for final tightening. The torsion-shear groove at the tail of the bolt is cut off by the wrench to ensure that the fastening torque meets the design requirements, with convenient operation and high precision;
- For large hexagon head steel structure bolts (the original expression "torque type" is not standardized and has been corrected), a torque electric wrench must be used for final tightening, and the final tightening torque must be strictly controlled to ensure the stability of the bolt connection.
It should be particularly noted that when using an electric wrench for final tightening, the operator must be proficient in the designed fastening torque of the bolt to avoid tensile deformation and fracture of the bolt shank due to excessive tightening, or loose connection due to insufficient tightening, which may cause potential construction safety hazards.
In summary, as a crucial connector in steel structure projects, steel structure bolts are widely used. In the process of purchase and use, it is necessary to fully understand their classification characteristics and construction specifications, and standardize the operation process, so as to effectively avoid installation misunderstandings, reduce various problems in use, and ensure the safety and stability of steel structure projects.
