Double-ended stud bolt operation methods and key points analysis
Preparatory work before operation is the foundation for successful installation. First, double-ended stud bolts with specifications, materials, and strength grades matching the design requirements should be selected, and their appearance should be checked for defects such as cracks, corrosion, thread damage, or shank deformation. The matching nuts and washers should also be verified one by one to ensure their dimensions match the bolt threads. For working environments with corrosive, high-temperature, or vibrating factors, appropriate protective greases, anti-loosening agents, or sealing materials should be prepared in advance. Simultaneously, the hole diameter, hole depth, and relative positional accuracy of the connected parts should be confirmed to avoid stress concentration or poor thread engagement due to hole position deviations.
During formal installation, one end of the double-ended bolt is typically passed through a pre-fixed through-hole in the substrate or embedded part, and a nut is screwed into that end for initial fixation. The bolt should be kept vertical during this process to prevent misalignment and thread jamming. The other end is then passed through the component to be connected, again with a washer and nut. For applications requiring precise positioning, the unthreaded section or locating shoulder of the bolt shank can be used as an axial limit to ensure that the clearance and coaxiality between the connected components meet design values. Tightening should be performed using a suitable torque tool, applying force gradually according to the specified tightening sequence and graded preload, avoiding overtightening at once which could cause thread stripping or shank bending. In areas subjected to dynamic loads or vibration, anti-loosening devices or thread-locking agents should be used between the nut and bolt to suppress preload decay during use.
Disassembly should be performed carefully and systematically. The nut at the movable end should be released from the connected component first, followed by loosening the nut at the fixed end. For bolts that have been in service for a long time or in corrosive environments, a penetrating lubricant can be sprayed before disassembly to alleviate resistance caused by thread corrosion. Avoid forceful hammering or excessive tightening to prevent damage to the threads or the bolt itself. After disassembly, bolts should be thoroughly inspected to assess their reusability. Bolts with severe wear, thread deformation, or fatigue cracks should be scrapped.
Quality control is crucial throughout the entire operation process. After installation, torque should be rechecked to ensure the design clamping force is achieved. Sampling tests should be conducted on critical structural connections to verify actual load-bearing capacity. Construction records should include bolt specifications, installation date, tightening parameters, and test results to provide a basis for subsequent maintenance.
In summary, the operation method for double-ended bolts covers preparation, installation, tightening, disassembly, and testing, emphasizing accurate selection, standardized processes, controllable torque, and adequate protection. Strict adherence to these points can effectively ensure the reliability and safety of connections and extend their service life.