Aluminum Office Chair Installation

Refer to the following steps for the installation of an aluminum office chair, ensuring strict adherence to the process for structural stability:

1. Prepare Materials and Tools
Gather all components in advance, including:

• Aluminum Profiles: 1 piece of 40280 (main support bar), 2 pieces of 40120 (side support bars);
• Connectors: 4 triangular brackets, 1 40*120 connecting bracket, 6 convex positioning blocks (for triangular and connecting brackets), 4 spring nuts (for cushion fixation);
• Fasteners: M820 screws (for most connections), M825 screws (for fixing bottom triangular brackets), M8 self-locking nuts (for caster fixation), thin nuts (for caster reinforcement);
• Other Components: Casters, cushion.
  Recommended Tools: Equip with an Allen wrench or screwdriver for tightening screws.

2. Install Triangular Brackets and Side Support Bars

• Step 1: Install convex positioning blocks on each corner of the triangular brackets, ensuring they are flush with the bracket surface.
• Step 2: Fix the triangular brackets to the ends of the two 40*120 aluminum profiles, ensuring the bracket surface is fully aligned with the profile surface.
• Step 3: Use spring nuts and M8*20 screws to pass through from the inside of the aluminum profile to the outside, and screw them into the threaded holes of the triangular brackets. Tighten symmetrically to avoid tilting.

3. Assemble the Main Support Structure

• Step 1: Align the two 40120 aluminum profiles with installed triangular brackets and insert them into the ends of the 40280 main support bar, ensuring both sides are 80 millimeters from the end of the main bar (centered installation).
• Step 2: Use spring nuts and M8*20 screws to fix the side support bars from the inside of the main bar to the outside, checking for vertical alignment and no gaps at the connections.

4. Install Connecting Bracket and Bottom Triangular Brackets

• Step 1: Install 6 convex positioning blocks on the 40*120 connecting bracket in a 'horizontal on both sides, vertical in the middle' pattern to enhance structural stability.
• Step 2: Align the connecting bracket with the intersection of the two side support bars and fix it with M8*20 screws, ensuring the connecting bracket is flush with the aluminum profile surface.
• Step 3: Take four uninstalled triangular brackets, place them bottom-down below the connecting bracket, and screw them from the top of the triangular brackets into the threaded holes of the connecting bracket with M8*25 screws. Tighten in a staggered manner to prevent uneven force.

5. Fix Casters

• Step 1: Place an M8 self-locking nut into the threaded hole of the bottom triangular bracket, screw in the caster from the outside, and hand-tighten until it cannot rotate.
• Step 2: Tighten again with a thin nut from the outside of the caster, forming a double-nut anti-loosening structure to ensure the wheel rotates flexibly without wobbling.

6. Install Cushion

• Step 1: Insert a spring nut into each corner of the cushion, and align the cushion diagonally with the top of the main support bar.
• Step 2: Pass an M8*20 screw through the cushion hole and screw it into the spring nut, tightening the diagonal screws first, then the remaining screws, and finally adjusting the cushion to a horizontal position.

Precautions:

• Regularly check for alignment of components during installation to avoid structural looseness due to misalignment.
• Tighten all screws to a secure state, but avoid excessive force that may deform the aluminum profiles.
• After installation, gently shake the chair to test stability, focusing on the connecting bracket and caster areas.