Office Chair Base Assembly

The office chair base is the core adjustment hub of an office chair, responsible for connecting the seat, gas lift, and five-star base, and enabling various adjustment functions.

I. Base Material and Structure The main body of an office chair base typically employs a metal frame formed through low-carbon steel tube welding or aluminum alloy die-casting. The low-carbon steel tube welded base offers high strength and stability, capable of withstanding significant pressure and weight, making it suitable for long-term use scenarios. The aluminum alloy die-cast base, on the other hand, is lightweight, corrosion-resistant, and features high machining precision, allowing for more complex structural designs, often used in high-end ergonomic chairs.

II. Core Functions

1. Seat Height Adjustment: Achieved by controlling the gas lift. Users can operate the adjustment lever on the base to move the seat up or down under the action of the gas lift, accommodating users of different heights.
2. Backrest Recline (Tilt): The base is equipped with a tilt mechanism that enables the backrest to recline, allowing users to relax their back muscles during rest.
3. Recline Angle Locking: The base provides multi-position or infinite locking options. Multi-position locking allows users to select fixed recline angles, such as 90°, 105°, 120°, etc., while infinite locking enables locking at any angle, offering a more flexible user experience.
4. Recline Tension/Resistance Adjustment: Users can adjust the knob or lever on the base to control the tightness of the recline. Heavier users can increase the tension to prevent rapid recline, while lighter users can decrease the tension for easier recline.

III. Intelligent Functions of High-End Bases The bases of ergonomic chairs are more refined and intelligent. High-end bases (such as synchronized bases or synchronous tilt mechanisms) feature synchronous tilt functionality: when the user reclines, the backrest and seat cushion intelligently联动 (link in motion), automatically maintaining proper lumbar support without manual adjustment, achieving dynamic adaptive support. This design effectively reduces fatigue caused by prolonged sitting and enhances user comfort.

IV. Market Types and Prices There is a wide variety of office chair base assemblies on the market, with significant price differences. For example:

• Aluminum alloy trays, priced at approximately ¥47.0, come with material guarantees and a 7-day replacement service.
• Rotating and height-adjustable bases (butterfly trays with handles), priced at approximately ¥18.0, are suitable for basic functional needs.
• Iron spray-coated trays, priced at approximately ¥9.0, are an economical choice that still offer height adjustment and rotation functions. Users can select the appropriate base type based on their budget and functional requirements.