What Size Are Office Chair Screws

The commonly used metric sizes for office chair screws are M4, M5, M6, M8, etc. Among them, M6 hex socket screws are mostly used for general connections, while M8 screws are commonly used for load-bearing parts (such as the base or casters). Here are the specific sizes and applicable scenarios:

1. M6 Screws: Suitable for Lightweight Structures

M6 screws are one of the most common sizes in office chairs, primarily used for connecting wooden frames or lighter chairs. They have a diameter of 6 millimeters and a length typically ranging from 25mm to 30mm, meeting the assembly needs of standard office chairs.

• Load-Bearing Capacity: M6 screws are designed to support approximately 100kg, making them suitable for chairs used by individuals with lighter weights or in low-frequency usage scenarios in daily office settings.
• Accompanying Tools: An S5 (5mm) hex key is required for installation, which is easy to operate and readily available.
• Application Scenarios: They are commonly used for connecting the backrest to the seat plate, fixing armrests, and assembling lightweight metal frames in non-load-bearing parts.

2. M8 Screws: Suitable for Heavy-Duty Structures

M8 screws have a diameter of 8 millimeters and a length typically ranging from 35mm to 40mm. Due to their higher strength and stability, they are widely used in parts with high load-bearing requirements.

• Load-Bearing Capacity: M8 screws can withstand heavier loads, with a design load capacity typically exceeding 100kg, making them suitable for connecting key load-bearing parts such as metal frames, bases, or casters.
• Accompanying Tools: An S6 (6mm) hex key is required, ensuring a secure fit between the tool size and the screw specifications.
• Application Scenarios: They are commonly found in the connection between the base and the gas lift of high-end office chairs, caster fixation, or chairs used by heavier individuals to enhance overall structural stability.

3. Other Sizes and Considerations

• M4/M5 Screws: These are less commonly used for the main structure and are more often seen in fixing small accessories (such as decorative caps or adjustment knobs).
• Length Selection: The screw length should be adjusted according to the material thickness. Too short a screw may result in an insecure connection, while too long a screw may affect structural stability.
• Material and Rust Prevention: Office chair screws are usually made of carbon steel or stainless steel. If used in humid environments, stainless steel screws are recommended to prevent rust.

Summary: The selection of office chair screw sizes should be based on the chair's material, load-bearing requirements, and usage scenarios. Lightweight chairs should prioritize M6 screws, while heavy-duty or metal-framed chairs should use M8 screws. Ensure that the corresponding size of hex key is used for installation.