Components Under an Office Chair
The bottom of a standard office chair typically consists of three main parts: the chair base, casters, and gas lift cylinder, with some models also including a seat pan. Common styles include five-star bases, bow bases, fixed wooden bases, and swivel seat pans. Here is a detailed introduction:
Chair Base: This is the key part that supports the entire structure of the office chair. Common materials include metal (such as steel or aluminum alloy), nylon, or solid wood. Metal chair bases offer strong load-bearing capacity and durability, with surface treatments like polishing, baking paint, or electroplating to prevent rust and extend service life. Nylon chair bases are lightweight and quiet, suitable for scenarios with low requirements for moving noise. Solid wood chair bases are often used in high-end models, enhancing product texture with natural materials. The bottom of the chair base usually adopts a five-star design (five-claw structure), which evenly distributes pressure and provides more stable support.
Casters: Installed at the ends of the chair base, casters directly affect the chair's mobility. Depending on the usage scenario, they can be classified as standard casters and PU casters. Standard casters are suitable for hard floors (such as tiles or concrete floors) and are cost-effective. PU casters, made of soft materials, are quiet when moving and reduce scratches on wooden floors, making them a common choice for home office settings. All casters support 360ยฐ rotation, ensuring the chair can be adjusted flexibly in direction.
Gas Lift Cylinder (Height Adjustment Cylinder): Located at the center of the chair base, this is the core component connecting the seat pan and the chair seat. It is filled with high-pressure gas and allows for height adjustment of the seat through pressing a handle or rotating operations. For gas lift cylinders with a lever, you usually need to lift the adjustment lever upwards and use your body weight to lower the seat. For those with a knob, turning it clockwise usually lowers the height, while turning it counterclockwise raises it. Some high-end gas lift cylinders also integrate a swivel function, supporting 360ยฐ free rotation.
Seat Pan: Although not directly exposed on the bottom appearance, the seat pan plays an important role in connecting the gas lift cylinder and the chair seat, as well as controlling the recline angle. Depending on the design, seat pans can be classified as fixed or adjustable. Fixed seat pans have a simple structure and are cost-effective. Adjustable seat pans, on the other hand, control the recline resistance through levers or knobs, meeting users' personalized needs for sitting comfort.
