Installing the flange nuts (with teeth) should follow the specified procedures to ensure a secure connection and meet the anti-loosening requirements. At the same time, it is necessary to avoid damaging the nuts or the connected components. Here is the detailed installation process and precautions:

I. Pre-installation Preparation

Check the condition of the accessories

Confirm that the specifications and materials of the flange nuts (with teeth) match those of the corresponding bolts / screws (with consistent thread size and tooth profile, such as M10 nuts paired with M10 bolts).

Check whether the teeth of the nut are in good condition: the tooth part should be without deformation or damage, the thread should be without rust or slippage, and the flange surface should be flat without cracks.

Inspect the surface of the connected parts: The surface should be clean, free of oil stains or thick rust (otherwise it will affect the "clamping" effect of the teeth), and the surface can be lightly sanded with sandpaper to make it smooth.

Preparation tools

Basic tools: Select the appropriate wrench based on the size of the nut (such as a hexagonal wrench or a socket wrench; avoid using a adjustable wrench as it may cause the nut to slip and deform).

Auxiliary tools: If there is a torque requirement, a torque wrench must be prepared; if the surface of the connected parts is prone to being scratched, a soft cloth (to wrap the wrench to prevent bumps) should be prepared.

II. Installation Steps

Align the connection position

Pass the bolts / screws through the through holes of the connected components, ensuring that the threaded part protrudes to a sufficient length (generally, it should extend 2-3 tooth pitches beyond the nut to avoid the risk of loosening due to excessive length, and if it is too short, the connection strength will be insufficient).

Manual pre-tightening of nuts

Hold the flange nut and position the teeth-facing side towards the surface of the connected component (key point: the teeth must make direct contact with the connected component; it must not be installed upside down, otherwise the anti-loosening function will be lost).

Rotate the nut clockwise by hand until the threads are engaged and cannot be turned any further manually (the purpose of pre-tightening is to avoid misalignment and to prevent damage to the threads when the subsequent tools are tightened).

Tool tightening (core step)

If there is a specified torque value (such as 50-80 N·m in the automotive industry), use a torque wrench to tighten it to the standard value:

Grip the wrench firmly on the hexagonal surface of the nut, and apply force slowly to ensure that the torque rises uniformly to the specified value (avoiding excessive force application at once which could cause the thread to deform).

If there is no specific torque value, it can be tightened based on experience: for small sizes (M3-M6), use a regular wrench to tighten until it feels "firmly tight"; for medium and large sizes (M8 and above), apply moderate force to ensure that the tooth pattern on the flange surface is embedded in the surface of the connected component (a slight indentation can be observed).

Check the installation effect

After tightening, visually check if the nut is skewed.

Gently shake the connected component to check for any signs of loosening; if possible, re-tighten it with a torque wrench to ensure that the torque has not decreased.

III. Installation Precautions

Prohibit reverse installation

The teeth should face the connected component. If the smooth surface is placed downward instead, the teeth cannot fit into the surface and the anti-loosening function will be lost. In an environment with vibrations, it is very likely to loosen.

Avoid over-tightening

Exceeding the specified torque may result in: thread slippage, flange deformation, surface crushing of the connected components (especially for soft materials such as aluminum and plastic), and even tooth fracture.

If you notice that the resistance suddenly decreases when tightening, it may indicate that the thread has been damaged. In this case, you should immediately stop and replace the nut and bolt.

Protect the surface of the connected parts

For brittle materials (such as ceramics and glass fibers), the tightening force should be controlled to avoid the teeth from penetrating too deeply and causing surface cracking (a thin metal sheet can be placed on the contact surface for buffering).

When installing stainless steel nuts, if the connected component is carbon steel, it is recommended to apply anti-clogging agent (to prevent corrosion caused by contact between different metals).

Other environmental processing

Damp or outdoor environment: Before installation, remove any moisture and impurities from the threads and contact surfaces. You can apply anti-rust grease to the threads (provided that it does not affect the meshing of the teeth).

High-temperature environment (such as around the engine): It is necessary to use nuts made of materials that can withstand high temperatures (such as high-temperature alloys), and regularly check the torque (high temperatures may cause metal creep, resulting in torque reduction).

Prohibit reuse (key point)

The tooth pattern of the serrated flange nut has already been embedded in the surface of the connected component during the initial installation. After disassembly, the tooth shape may deform, and repeated use will significantly reduce the anti-loosening effect. For critical parts (such as car wheels, lifting equipment), new nuts must be replaced.