Office Chair Assembly

It is generally recommended to assemble office chairs from the bottom up. Taking the Sihoo ergonomic chair as an example, the assembly steps are as follows:

1. Install the Chair Base and Gas Lift
   Press or screw each caster (wheel) into the mounting holes on the chair base one by one, ensuring that each wheel is secure and does not wobble. After assembling the chair base, insert the gas lift vertically into the center hole of the chair base. Note that the metal end of the gas lift should face down, and the plastic end should face up, providing stable support for the installation of subsequent components.

2. Secure the Seat and Base Plate
   Align the base plate (which includes modules for controlling height adjustment and recline functions) with the screw holes on the bottom of the seat. Use the provided screws to secure it. Ensure that the screws are tightened properly to prevent any wobbling between the base plate and the seat, which could affect safety during use.

3. Attach the Backrest to the Seat
   Align the metal bracket of the backrest with the mounting holes at the rear of the seat and secure it with screws or clips. For some models (such as the Sihoo M88C), you need to first insert a pin through the connection holes between the backrest and the gas lift, and then secure the pin with a clip to ensure that the backrest can be adjusted flexibly.

4. Install the Armrests and Headrest

   • Armrest Installation: Align the armrests with the预留 (pre-drilled) holes on the sides of the backrest. Insert them and then secure them from the outside with screws (such as M8*39 model). Cover the screw heads with screw caps to keep the appearance neat.
   • Headrest Installation: If the chair is equipped with a headrest, insert its bracket into the slot or screw hole at the top of the backrest and adjust it to the appropriate height before securing it.

5. Final Assembly and Testing
   Align the upper part of the assembled chair (including the seat, backrest, and armrests) with the top of the gas lift and press down vertically to snap it into place. After installation, test each function:

   • Pull the handle of the gas lift to adjust the chair's height;
   • Pull the handle outward to adjust the recline angle of the backrest;
   • If equipped with a footrest, pull it out and flip it upward for use;
   • Adjust the height of the lumbar support (for some models, you need to hold the handle of the lumbar support and pull it to the top before returning it to its original position).

Precautions: Before assembly, check that all parts are complete to avoid missing screws or tools. Keep the components vertically aligned during installation to prevent tilting, which could lead to an unstable structure. If you encounter difficulty in securing clips or screws, check that the holes are aligned properly to avoid damaging the components by forcing them.