What effect does the external thread design of an insert nut have on its retaining performance?

The external thread design of the insert nut has a great impact on its retaining performance. The thread design not only affects the fixation effect of the insert nut in the material, but also determines its stability and durability in different application environments. The type of thread is critical when selecting the appropriate insert nut. Straight threads are often used on metallic materials because they provide a stable threaded connection suitable for bearing larger loads. For soft materials, such as wood or plastic, tapered threads and self-tapping threads are more suitable. Tapered threads provide stronger retention by increasing the contact area with the material through gradually increasing diameters. Self-tapping threads form threads in the material by cutting themselves. This design allows the nut to lock directly in the material, thereby achieving a stable fixation.

The spacing and pitch of the threads also have a significant impact on fixation performance. Threads with a smaller pitch can provide more contact surfaces and increase friction, thereby improving the fixing effect. Conversely, larger thread pitches are suitable where quick installation is required, but may exhibit weaker holding properties under load. This is because threads with larger pitches have fewer contact surfaces and relatively smaller friction. The depth and height of the threads are also critical factors. Deeper threads can provide a larger contact area and stronger biting force, suitable for high-strength connection needs. Shallow threads may loosen easily under high load conditions, affecting the stability of the connection.

The surface treatment of the threads is equally important. Through galvanizing, nickel plating or other anti-corrosion coating treatments, the corrosion resistance of the thread is improved, while the surface friction is increased, helping to improve the fixing effect. Surface treatment can prevent thread performance degradation due to corrosion during use and extend the service life of the nut. The angle and profile design of the thread are also important factors affecting the fixation performance. A smaller thread angle can increase friction and bite force, providing a tighter connection, while a larger thread angle is suitable for quick installation and disassembly, providing convenience. The design of the thread profile, such as square, trapezoidal or triangular cross-section, can be optimized according to specific application requirements to achieve the best fixing effect.