Office Chair Foot Technology

Office chair foot technology mainly involves two aspects: material selection and static pressure technical indicators.

Material Selection

• Nylon Chair Feet: These are formed using injection molding, achieving a one-piece structure without welding. They are lightweight, weighing approximately 0.8 - 1.5kg, resulting in low moving inertia. They are non-conductive, ensuring good safety. They are resistant to moisture and chemical corrosion, with relatively low costs, making them suitable for large-scale matching. After high-strength treatment, they are often used in automotive engine components and aviation equipment parts. However, they may become brittle under long-term heavy pressure or in low-temperature environments (this can be improved by adding glass fibers to high-quality nylon), and their surfaces are prone to scratches. They can be identified by the injection molding points at the bottom of the feet, with colors mostly being black or dark gray (some can be made white or colored).
• Steel Chair Feet: These are made by bending and welding steel pipes or stamping and welding steel plates, with surfaces that are either powder-coated or electroplated (with chromium). They have high strength, are not prone to breakage, and have strong load-bearing capacity. After powder coating, their corrosion resistance is acceptable. However, they are relatively heavy, weighing about 2 - 3kg, making them laborious to move. If the welding points are not properly treated, they may rust, and the electroplated versions are prone to fingerprints. They can be identified by being attracted to a magnet, with visible metallic luster on the cross-section and traces at the welding points.
• Aluminum Alloy Chair Feet: These are formed through die-casting, followed by polishing, wire drawing, or spraying treatments. They have high strength and moderate weight, weighing about 1.5 - 2.5kg. They never rust and are resistant to aging. They have a good appearance and texture, often presenting the original metal color or a bright finish. They are the most expensive to manufacture, have the best load-bearing capacity, are environmentally friendly and recyclable, and are widely used in mid-to-high-end office chairs and ergonomic chairs. However, their cost is relatively high, about 2 - 4 times that of nylon feet, and die-casting defects may affect their strength, so it is necessary to choose reputable manufacturers. They can be identified by their non-magnetic nature (pure aluminum is non-magnetic), silver-white cross-section, and clear knocking sound.

Static Pressure Technical Indicators

• Core Definition: This refers to the mechanical properties of an office chair's five-star foot when subjected to vertical static pressure, including maximum load-bearing capacity, deformation, stress distribution, fatigue life, etc. It reflects its ability to resist deformation and breakage and is the foundation for ensuring safety and stability.
• Testing Principle: Using professional pressure testing equipment, the five-star foot is fixed on a testing platform. A gradually increasing vertical pressure is applied through a hydraulic or mechanical loading device, and sensors are used to continuously monitor the pressure value, deformation, and stress changes until obvious deformation, cracks, or breakage occur. Data such as the ultimate load-bearing capacity and deformation curves are obtained. Some tests also consider the pressure distribution at different angles and loading points.
• Key Indicators: The maximum load-bearing capacity. For ordinary office chair five-star feet, it should be no less than 1136N (about 116kgf). For those suitable for heavy individuals or high-intensity usage scenarios, it should reach 1500N (about 153kgf) or more. Regarding deformation, when subjected to the rated pressure (e.g., 1136N), the vertical deformation should not exceed 2mm, and the horizontal deformation should not exceed 1mm.