Assemble Office Chair

The assembly of the 999B office chair requires preparing the matching materials and installing the armrests and base in sequence according to the video instructions. The specific steps are as follows:

I. Pre-assembly Preparation

1. Material Verification: According to the product manual or installation video, confirm that all accessories are complete, including screws P, screws L, gaskets G (for armrest installation), screws F (for base installation), as well as main components such as the seat, armrests, base, and five-star foot. If any accessories are missing, contact the merchant for replenishment to avoid interruption during assembly.
2. Tool Preparation: Typically, a Phillips screwdriver or electric screwdriver is required. Some screws may need to be tightened manually. Ensure that the tools match the screw specifications (e.g., Phillips or flat-head slots).
3. Environment Inspection: Choose a flat and spacious ground for assembly to prevent components from rolling or tipping over. Clear surrounding clutter to avoid collisions during operation.

II. Armrest Installation Steps

1. Positioning Armrests and Seat: Lay the seat flat and align the armrests with the reserved holes on both sides of the seat, ensuring the correct orientation of the armrests (usually the inner side of the armrests faces the center of the seat).
2. Combining Gaskets and Screws: Place gasket G over screw P or screw L (according to the type specified in the video). The gasket should completely cover the underside of the screw head to distribute pressure and prevent the screw from loosening.
3. Securing Armrests: Insert the combined screw through the hole at the bottom of the armrest and screw it into the corresponding threaded hole in the seat. Tighten in stages: First, manually screw it in until the screw cannot wobble, then use a tool to apply even force to avoid tilting the armrest due to excessive force on one side.
4. Symmetrical Operation: When installing the armrest on the other side, maintain consistent force to ensure that both sides are at the same height and angle. This can be checked visually or with a level.

III. Base Installation Steps

1. Connecting Base and Seat: Align the base (with the gas lift interface) with the center hole at the bottom of the seat, ensuring that the fixing holes of the base completely overlap with the reserved holes in the seat.
2. Securing with Screw F: Take screw F (usually a larger screw) and insert it through the hole in the base and screw it into the threaded hole in the seat. Tighten in a diagonal sequence in stages: First, tighten the two diagonal screws, then tighten the remaining screws in sequence to ensure even force distribution on the base and prevent deformation.
3. Checking Stability: After installation, gently shake the base to confirm that there is no looseness or abnormal noise. If wobbling is detected, recheck whether the screws are tightened or whether the holes are aligned.

IV. Subsequent Assembly Tips

After completing the installation of the armrests and base, refer to the video to continue installing components such as the five-star foot, gas lift, and wheels. Strictly follow the video instructions during the installation process, especially regarding screw specifications and tightening sequences. Incorrect operations may lead to structural instability or damage to components. If you have any questions about the steps, it is recommended to pause the installation and contact customer service for clarification.