How to Assemble an Office Chair

The steps for assembling an office chair are as follows:

1. Install the casters and chair base
   Insert each caster into the mounting holes of the five-pronged chair base one by one. Ensure that each caster is fully seated in the hole to prevent looseness. After installation, place the gas lift vertically into the central hole of the chair base, making sure the bottom of the gas lift is in close contact with the chair base to provide a stable foundation for subsequent support.

2. Install the seat plate and seat
   Place the seat plate at the bottom of the seat. Pay attention to the orientation of the seat plate (usually there are markings or grooves corresponding to the seat structure). After aligning the screw holes, use a screwdriver to screw each screw in 3 - 4 turns to ensure all screws are initially fixed, and then tighten them one by one until fully secured. Avoid tilting the screws or leaving them loose in this step to prevent the seat plate from becoming loose.

3. Connect the backrest and seat
   Align the two sides at the bottom of the backrest with the armrest mounting positions on both sides of the seat, and slowly insert them until the bottom catches are fully engaged. First, use screws to fix the bottom of the backrest from the bottom of the armrest brackets to ensure an initial connection. Then, align the mounting holes at the back of the backrest with those on the seat brackets. Use two wrenches (or matching tools) to lock the screws in place, ensuring that the backrest and seat are firmly connected without any wobbling.

4. Install the base and gas lift
   Align the seat with the connected backrest with the top of the gas lift and insert it vertically into the hole in the seat plate, ensuring full contact between the gas lift and the seat plate. Then, vertically slide the chair base (with casters) over the bottom of the gas lift and gently press down until it is fully seated, forming a complete support structure. In this step, check whether the gas lift is vertical to avoid instability during use due to tilting.

5. Install the armrests and headrest
   Press the button below the armrest surface and insert the left and right armrests into the holes of the armrest brackets respectively. A "click" sound indicates that they are properly installed. When installing the headrest, place it in the middle position at the top of the backrest, gently press to make the installation area fit snugly, and use screws to pass through the headrest fixing catches. First, screw each screw in 3 - 4 turns for initial fixation, and then tighten them completely. In this step, ensure that the height of the headrest is adjustable (if designed so) and that the screws are tightly secured without looseness.

Precautions: Avoid using excessive force during the installation process to prevent damage to the parts. All screws should be tightened until there is no wobbling, but avoid over-tightening to prevent thread stripping. After installation, check whether all components are firmly connected and whether the gas lift can move up and down smoothly.