When punch-free threaded rods are used for temporary fixation, the primary consideration in selection is the convenience of installation and disassembly, and the requirements for load-bearing capacity are relatively loose. Temporary fixation is mostly suitable for short-term support, positioning or maintenance scenarios, such as temporary fixation during equipment assembly. At this time, the threaded rod does not need to bear continuous high-strength loads, and more attention is paid to rapid installation and non-destructive removal. Therefore, models with lower thread density and lighter head design can be selected. Such threaded rods do not need to be over-tightened during installation, and can also reduce friction on the substrate during disassembly. At the same time, threaded rods for temporary fixation usually do not require complex anti-loosening structures. Simple thread self-locking design can meet the needs and avoid cumbersome operations caused by complex structures.
In long-term load-bearing scenarios, the core of punch-free threaded rod selection is material strength and structural stability. It is necessary to ensure that it can withstand continuous loads without deformation or fracture. When bearing loads for a long time, threaded rods have to face constant tension or pressure. The tensile strength and yield strength of the material become key indicators. Models with tougher materials should be selected, such as threaded rods made of high-strength alloy steel, whose molecular structure is more stable and can maintain their shape under long-term stress. In addition, long-term load-bearing threaded rods need to undergo strict heat treatment processes to improve the hardness and wear resistance of the material, avoid thread wear due to long-term use, and affect the reliability of the connection.
There are significant differences in the selection of thread design between temporary fixation and long-term load-bearing. Temporary fixed threaded rods can use shallower thread profiles and wider thread spacing. This design can reduce the resistance during installation, facilitate quick screwing into the base, and prevent the base material from sticking due to excessive thread depth during disassembly. Long-term load-bearing threaded rods need to adopt deep thread profiles and dense thread designs. Deep thread profiles can increase the contact area with the base and increase friction. Dense threads can disperse the load, avoid deformation of the thread due to excessive local stress, and ensure stability during long-term stress.
The two also have different focuses on the matching selection of length and diameter. When temporarily fixed, the length of the threaded rod only needs to be slightly longer than the connection thickness. Too long will increase the difficulty of operation. The diameter can also be appropriately reduced to reduce the pressure on the base and reduce the traces left after temporary fixation. For long-term load-bearing, the appropriate length and diameter need to be calculated according to the actual load. Usually, the larger the diameter, the more accurate the length, to ensure that the threaded rod can penetrate deep enough into the matrix to form a stable support. At the same time, the ratio of diameter to connection thickness needs to meet the mechanical requirements to avoid excessive force per unit area due to too small diameter, which may cause the matrix to crack.
The difference in material selection is an important sign to distinguish between temporary and long-term selection. Temporary fixation can use ordinary carbon steel with lower cost, and the surface treatment can also be simplified. For example, simple galvanizing can meet the short-term anti-rust requirements. For long-term load-bearing, it is necessary to select a more corrosion-resistant material according to the use environment. For example, stainless steel is used in a humid environment. It has a high chromium content and can form an oxide film to resist rust; in a high temperature environment, heat-resistant alloy materials are required to avoid the degradation of material performance due to temperature changes, which affects the load-bearing stability.
The selection of anti-loosening structure is significantly different in the two scenarios. Temporary fixed threaded rods do not require additional anti-loosening devices, and rely on the friction of the thread itself. If anti-loosening washers or nuts are added, it will increase the difficulty of disassembly and do not meet the convenience requirements of temporary use. Long-term load-bearing threaded rods must be equipped with reliable anti-loosening structures, such as double nut locking, anti-loosening washers or thread glue treatment. These designs can effectively resist loosening caused by factors such as vibration and temperature changes, ensuring that the connection is always firm during long-term use. Especially in key parts such as industrial equipment and building structures, anti-loosening structures are necessary considerations for selection.
The selection considerations for substrate adaptability also vary depending on the scenario. The temporary fixed punch-free threaded rod has a wider adaptability to the substrate material, and can be selected even for substrates with lower strength (such as plastics and lightweight wood). As long as it can meet the short-term fixing requirements, there is no need to over-consider the long-term bearing capacity of the substrate. Long-term load-bearing must be selected according to the strength characteristics of the substrate material. For example, in a concrete substrate, a threaded rod that can tightly bite the concrete needs to be selected. Its surface may have special patterns or coatings to enhance the bonding strength with the substrate; in a metal substrate, the compatibility of the threaded rod and the metal needs to be considered to avoid electrochemical corrosion affecting long-term stability.
