Office Chair Backrest Screw

Answers to common questions about office chair backrest screws are as follows:

Causes of Looseness and Targeted Solutions Common causes of looseness in office chair backrests include loose adjustment rod screws, fatigue in the backrest spring, or aging of the gas lift. If the backrest wobbles significantly when reclining and is accompanied by a 'clicking' sound, over 90% of the cases are caused by the adjustment rod screws not being tightened properly. In this case, use a Phillips screwdriver to rotate the plastic cover at the base connection counterclockwise, expose the metal bracket, and then use a wrench to tighten the 6-8 fixing screws one by one. It is recommended to tighten them symmetrically at 90° intervals (e.g., tighten the screw at the 12 o'clock position first, then the 3 o'clock, 6 o'clock, and 9 o'clock positions) to avoid deformation of the metal bracket due to unilateral force. If the backrest remains loose after tightening, check whether the backrest spring is broken or whether the gas lift is leaking. In such cases, the parts need to be replaced.

Types of Screws and Installation Specifications Taking a single-back chair with screw adjustment as an example, its backrest installation involves two types of key screws:

1. Screws connecting the backrest rod to the chair legs: Four A2 screws (usually M6×20 in size) and matching hexagonal Phillips wrenches are required. During installation, the back of the backrest tube should face backward, with the outer two holes fixing the seat plate and the inner two holes aligned with the holes on the chair legs. Tighten the A2 screws from the bottom up. Ensure that the screws fully penetrate the holes to avoid looseness due to unengaged threads.
2. Adjustment rod fixing screws: Some chairs have adjustment screws at the connection between the backrest and the gas lift to control the recline angle. These screws should be checked regularly. If thread wear is detected, replace them with high-strength stainless steel screws (e.g., 304 material).

Accessory Selection and Maintenance Recommendations Specialized office chair screw sets (such as those sold by Zhijiang Zhuangkang Trading Co., Ltd.) are available on the market, including a full set of fasteners such as screws, nuts, and washers. When selecting, note the following:

• Specification matching: Measure the diameter (e.g., M6, M8) and length (e.g., 20mm, 25mm) of the original screws to avoid mismatched models.
• Material selection: Prefer stainless steel or galvanized screws, which have better rust resistance than ordinary carbon steel.
• Maintenance cycle: It is recommended to check the tightness of the screws every 6 months. For chairs that are frequently adjusted (e.g., reclining types), the interval can be shortened to 3 months.

If the screw holes become stripped due to frequent disassembly and assembly, use metal adhesive to fill the threaded holes or replace them with thicker washers to enhance grip.