High-strength large hexagon head bolts for steel structures

High-strength large hexagon head bolts for steel structures are a type of fastener widely used in the connection of steel structures.

Characteristics of High-strength Large Hexagon Head Bolts for Steel Structures

High strength: They can withstand large tensile and shear forces, ensuring the reliability of steel structure connections. Generally, they are made of high-strength steel and undergo processes such as heat treatment to give them high yield strength and tensile strength.

Good fastening performance: The large hexagon head design facilitates tightening operations using tools such as torque wrenches, and the pre-tightening force of the bolts can be precisely controlled to ensure the tightness and stability of the connection.

Corrosion resistance: Usually, surface treatments such as galvanizing and nickel plating are carried out to improve the corrosion resistance of the bolts and adapt to different usage environments.

Specifications of High-strength Large Hexagon Head Bolts for Steel Structures

The specification dimensions usually include the thread diameter, length, etc. Common thread diameters are M12, M16, M20, M22, M24, M27, M30, etc., and there are various choices for the length according to specific usage requirements, generally ranging from 30mm to 300mm.

Applications of High-strength Large Hexagon Head Bolts for Steel Structures

They are mainly used in the connection of beams and columns in steel structure buildings, the connection of nodes of steel trusses, as well as in steel structure projects such as bridges and towers. For example, in the steel structure framework of large industrial plants, high-strength large hexagon head bolts connect the steel beams and columns together, bearing the self-weight of the building and various loads; in bridge structures, they are used to connect the steel structure components of the bridge to ensure the structural safety and stability of the bridge.

Construction Requirements for High-strength Large Hexagon Head Bolts for Steel Structures

Bolt hole processing: The bolt holes on steel structure components should be processed by drilling to ensure the accuracy and surface quality of the holes. The hole diameter should meet the design requirements to ensure that the bolts can be inserted smoothly.

Installation sequence: Generally, the installation should be carried out from the part with high stiffness to the unconstrained free end. First, install temporary bolts to fix the position of the components, and then gradually replace them with high-strength bolts and tighten them according to the specified torque.

Torque control: Use a torque wrench to tighten according to the torque value specified in the design to ensure that each bolt can reach the specified pre-tightening force. During the construction process, the torque wrench should be calibrated regularly to ensure the accuracy of torque control.

Construction environment: The installation of bolts should be avoided in rainy days or environments with high humidity to prevent the surface of the bolts from rusting and affecting the connection quality. When the ambient temperature is lower than a certain value, such as -10°C, corresponding measures such as preheating should be taken to ensure the construction quality.

Acceptance Standards for High-strength Large Hexagon Head Bolts for Steel Structures

Appearance inspection: The surface of the bolts should have no defects such as cracks, scars, and rust, and the threads should be complete and undamaged.

Torque inspection: Use the torque method or the angle-of-rotation method to inspect the tightening torque of the bolts, and the sampling quantity should meet the requirements of relevant standards. A certain proportion of bolts with torque deviations within the specified range are allowed, but bolts exceeding the range should be retightened or replaced.

Inspection of the connecting friction surface: The anti-slip coefficient of the connecting friction surface of the steel structure should meet the design requirements and can be inspected through on-site anti-slip coefficient tests.

The quality of high-strength large hexagon head bolts for steel structures and the construction quality are directly related to the safety and reliability of steel structure projects. Therefore, operations in all links such as design, material selection, construction, and acceptance should be carried out in strict accordance with relevant standards and specifications.