Ordinary Office Chair Installation

The installation steps for an ordinary office chair are as follows:

Step 1: Component Verification and Sorting
Before installation, carefully verify the quantity of components to ensure they match the instruction manual. Common components include: 1 backrest (or an integrated backrest and seat structure), 1 seat, 1 five-star base, 5 casters, 1 gas lift cylinder, 1 butterfly plate, 1 pair of armrests (2 pieces), several screws (including long and short screws and washers), and an optional headrest. If any components are missing or damaged, contact the merchant promptly for replacements to avoid interruptions during installation.

Step 2: Install Casters and Five-Star Base
Press each of the 5 casters firmly into the ends of the five legs of the five-star base. Some domestic casters may require significant pressure due to non-standard specifications to ensure they are fully embedded and secure. If installation is difficult, try using a rubber mallet to assist.

Step 3: Secure the Gas Lift Cylinder
Invert the five-star base with casters (casters facing up) and vertically insert the gas lift cylinder into the central hole of the five-star base. Some gas lift cylinders come with plastic protective covers, which should be installed simultaneously to protect the internal structure. The gas lift cylinder is the core component for chair height adjustment; ensure it is installed vertically to prevent air leakage or damage from tilting.

Step 4: Assemble Seat and Armrests
Place the seat flat and align the armrests with the pre-drilled holes on both sides of the seat (usually 3 holes per side), securing them with screws. Control the tightening force during installation, aiming for '90% tightness' to avoid cracking plastic parts from over-tightening. Place washers between the screws and the seat to distribute pressure and prevent loosening.

Step 5: Install Butterfly Plate and Backrest
Align the butterfly plate (base) with the mounting position on the bottom of the seat and secure it with long screws. If the backrest is separate from the seat, insert the backrest's connecting rod into the corresponding hole on the butterfly plate and tighten with screws. When installing the backrest, check that the connection is flush and that washers fully cover the contact surface to reduce noise.

Step 6: Overall Assembly and Adjustment
Align the seat (including armrests and butterfly plate) with the top of the gas lift cylinder and press down firmly to ensure full engagement. Lift the seat to test the height adjustment function and confirm the gas lift cylinder is working properly. If height adjustment is stuck, check if the gas lift cylinder is vertical or if the butterfly plate is misaligned.

Step 7: Install Headrest and Final Inspection
Insert the headrest into the pre-drilled hole at the top of the backrest, secure it with screws, and test the tightness by tapping. Finally, insert any remaining small screws (if any), which usually serve as safety measures to prevent component detachment. After installation, shake the chair left and right to check stability and tilt the backrest forward and backward to test flexibility, ensuring there is no looseness or noise.

Precautions:

1. Avoid using power tools during installation to prevent over-tightening or stripping screws.
2. If the chair design includes corner brackets (metal pieces connecting the backrest and seat), secure them with short screws and ensure they are fully flush with the backrest and seat.
3. Before first use, test the height adjustment and tilt functions without load to confirm safety before regular use.