Office Chair Bolt Sizes

The sizes of bolts for office chairs vary depending on the part and load-bearing requirements. Common specifications can be divided into three categories: ordinary connecting parts, load-bearing parts, and other parts, as detailed below:

Ordinary connecting parts usually use M6 standard hexagon socket screws. For example, the connection between the chassis and the seat frame commonly uses M6x25 (6mm in diameter and 25mm in length), the connection between the headrest and the back frame commonly uses M6x20 (6mm in diameter and 20mm in length), and home office chairs may also use the M6×12mm specification. These screws are suitable for non-high-strength force scenarios. The length selection should be adjusted according to the thickness of the connected parts. For example, thin plates are usually fixed with lengths of 10-20mm, while thicker parts require lengths of 25-40mm.

Load-bearing parts require stricter screw specifications due to the need to withstand greater torque. For example, the connection between the chassis and the backrest commonly uses M8x30 (8mm in diameter and 30mm in length). Some models may have M6 screws under the base, but actual measurement is required for confirmation. These screws have a larger diameter, which can effectively disperse pressure and prevent loosening or breakage after long-term use.

The screw specifications for other parts vary greatly. Non-load-bearing parts such as plastic chairs or armrest decorative pieces may use M3/M4 screws; metal chair legs or base connections require M5/M6 screws, and the specific choice should be based on the material of the parts and the load-bearing requirements. For example, metal-to-metal connections usually require higher-strength screws, while plastic part connections can have lower specifications.

Precautions:

1. Non-uniform specifications: Screw specifications may vary among different brands and models. It is recommended to measure the diameter (excluding the threaded part) and length of the old screws first before purchasing to avoid installation difficulties due to non-compliant specifications.
2. Tool matching: M6 screws usually correspond to a 5mm hexagon socket wrench, and M8 screws correspond to a 6mm wrench. Mismatched tools can easily cause slippage or damage to the screw head.
3. Regular inspection: The chassis of the chair bears a large load. It is recommended to check the tightness of the screws every six months, especially for office chairs that are frequently adjusted in height or reclined, to avoid safety hazards caused by loosening.

If you need to replace the screws, first confirm the type of the connected part (such as load-bearing or non-load-bearing), then select the appropriate length according to the thickness of the part, and finally match the wrench of the corresponding specification for operation.