Black Office Chair Screws

Black office chair screws come in a variety of types, with common specifications and characteristics as follows:

The materials and designs of black office chair screws need to meet the requirements of high strength, corrosion resistance, and adaptability to different structures. Common types include socket head cap screws, hex head screws, star-head rubber-capped screws, and self-tapping screws, with specific specifications varying according to the usage scenario.

1. Socket Head Cap Screws

• 12.9-grade black socket head cap set screws: Made of high-strength alloy steel with a hardness of 12.9 grade, suitable for structural connections requiring high load-bearing capacity, such as fixing the chair back to the seat. Their headless design (set screws) allows them to be hidden inside components, maintaining a clean appearance.
• M3/M4 recessed end set screws: Specified by diameter (M3/M4), the recessed end design can be embedded into component grooves to prevent slipping, commonly used for adjusting component positions, such as locking the tilt angle of the chair back.

2. Hex Head Screws

• M8*20 black zinc-plated 8.8-grade hex head screws: With a diameter of 8mm and a length of 20mm, the surface is treated with black zinc for both rust prevention and wear resistance. The 8.8-grade strength is suitable for connecting the chair legs to the base, and the anti-slip teeth design enhances friction to prevent loosening.

3. Star-Head Rubber-Capped Screws

• M8 star-head rubber-capped bolts: The head is in a pentagonal star shape, covered with black rubber for easy manual adjustment and anti-slip properties. Commonly used in the lifting mechanisms of office chairs, such as fixing the gas lift to the base, the rubber layer reduces metal friction noise.

4. Self-Tapping Screws

• Round-head self-tapping black screws: The pointed end can tap into materials (such as plastic or wood) by itself without pre-drilling, improving installation efficiency. Surface rust prevention treatment (such as electrophoretic black) extends the service life, suitable for connecting the seat to plastic accessories.

5. Specialized Backrest Bolts

• Black mesh office chair backrest bolts: With a diameter of 6mm and a length of 45mm, made of stainless steel for strong corrosion resistance. Specially designed for mesh chair backs, they can fix the backrest to the chair frame, ensuring structural stability.

Selection Advice:

• Choose the strength grade according to load-bearing requirements (e.g., 12.9 grade > 8.8 grade);
• In humid environments, prioritize stainless steel or rust-prevented screws;
• For parts requiring frequent adjustment (such as lifting and tilting), choose star-head rubber-capped or recessed end screws.