Office Chair Internal Nut

Answers to common questions about office chair internal nuts are as follows:

Office chair internal nuts typically refer to the fixing components that are paired with hexagon socket screws. Their specifications, application scenarios, and maintenance methods need to be analyzed in conjunction with the specific structure.

1. Common Specifications and Applicable Scenarios
Common hexagon socket screw specifications used in office chairs include M3, M4, M5, M6, etc. Different specifications correspond to different load-bearing requirements.

• M3 screws: With a diameter of 3 millimeters, they are suitable for non-load-bearing parts such as plastic chairs or armrest decorative pieces, like armrest cover plates and plastic backrest connections.
• M4 screws: With a diameter of 4 millimeters, they are used for lightly load-bearing structures, such as the connection between plastic chair legs and the seat plate.
• M5/M6 screws: With diameters of 5-6 millimeters, they are the core fixing components for load-bearing parts, such as the connections between metal chair legs and the base, and between the five-star foot and the gas lift.
  The length of screws usually ranges from 10-40 millimeters and should be selected according to the thickness of the fixed part. For example, a 20-30 millimeter M6 screw may be used at the connection between the chair leg and the base, while a 10 millimeter M3 screw may be sufficient for armrest decorative pieces.

2. Tool Selection and Operation Points
To disassemble or tighten hexagon socket screws, a matching hexagon socket wrench should be used, with the specification corresponding to the screw. For example:

• An M6 screw requires a 5 millimeter hexagon socket wrench. If the wrench does not match the screw slot, it may cause the screw to slip or damage the screw head.
• When operating, keep the wrench perpendicular to the screw to avoid applying force at an angle, which can cause the screw to slip.

3. Common Problems and Solutions

• Loose screws: After long-term use, screws may become loose due to vibration or wear. In this case, a spring washer can be added to increase friction through the elasticity of the washer and prevent the screw from backing out.
• Damaged threads: If the internal threads of the screw hole are stripped or worn, forcing the screw in will result in a failed fixation. A new screw needs to be replaced, and the material of the fixed part should be checked:
  • For metal parts, the threads can be retapped to repair them.
  • For severely damaged plastic parts, it is recommended to replace the entire accessory (such as the chair leg or base).

4. Safety Precautions

• Before disassembling screws from load-bearing parts (such as chair legs and gas lifts), place the chair on a stable surface to avoid tipping over.
• If the screws are rusted and difficult to disassemble, spray a small amount of loosening agent (such as WD-40) and wait for 5-10 minutes before operating. Do not forcefully pry it open.

By reasonably selecting screw specifications, matching tools, and performing regular maintenance, the structure of the office chair can be kept stable, and its service life can be extended.