Office Chair Leg Mortise and Tenon

The mortise and tenon structure of office chair legs is a typical application of traditional woodworking techniques in furniture. Its design takes into account both mechanical stability and craftsmanship aesthetics. The following are common types and their characteristics:

I. External Splayed Structure with Integrated Mortise and Tenon Connection

Some solid wood office chairs (such as Jiayi dining chairs) adopt an externally splayed leg design. By expanding the bottom support area, they enhance anti-tipping capabilities and achieve an integrated connection between the chair legs and crossbars through mortise and tenon joints. This structure precisely interlocks the tenon and mortise, converting vertical load-bearing into friction between wood fibers and structural integrity. The measured load-bearing capacity can reach 150KG, making it suitable for frequent use in daily office scenarios. Its core advantage lies in reducing the use of metal connectors, avoiding abnormal noises or structural failures caused by loose screws while preserving the natural texture integrity of the wood.

II. Application of Cylindrical T-shaped Joints

In new Chinese-style office chairs, cylindrical T-shaped joints are commonly used for connecting the footrests (horizontal support bars) to the legs. This mortise and tenon joint consists of a vertically oriented cylindrical tenon and a horizontally oriented mortise. After inserting the tenon into the mortise and rotating it to secure it, a three-dimensional restraining force is formed. Its characteristics include:

1. Simple styling: The tenon has the same diameter as the leg, with no protruding parts on the exterior, aligning with modern minimalist design trends;
2. Efficient mechanics: The contact surface between the tenon and mortise is cylindrical, distributing stress evenly under load and reducing the risk of cracking;
3. Process adaptability: High-precision machining can be achieved through CNC machines, making it suitable for mass production. Such structures are often found at the intersections of chair legs and crossbars, such as the connection nodes between the front legs and front crossbars of chairs.

III. Improved Application of Traditional Chinese Mortise and Tenon

Some office chairs borrow the mortise and tenon logic from Chinese round-back chairs, adopting a structure where the legs are directly assembled with the seat surface. For example, the top of the legs is processed into a dovetail tenon, which fits into a trapezoidal mortise at the bottom of the seat surface. The wedge-shaped design of the tenon achieves self-locking functionality. This structure relies on the natural elasticity of the wood. During installation, the insertion depth of the tenon must be controlled to ensure both a tight connection and space for disassembly. Its advantage lies in eliminating the need for adhesives, aligning with environmental protection concepts. However, strict material selection (such as hardwoods) is required to avoid loosening caused by tenon wear after long-term use.

Summary: The mortise and tenon structures of office chair legs achieve a balance between load-bearing capacity, stability, and aesthetics through the design of different joint types. The externally splayed structure reinforces bottom support, the cylindrical T-shaped joint simplifies horizontal connections, and the improved traditional joint continues cultural heritage. When making actual selections, it is necessary to comprehensively consider usage scenarios (such as load-bearing requirements and frequency of movement) and material characteristics (such as wood hardness and grain direction) to ensure the long-term reliability of the structure.