Office Chair Caster Replacement

Follow these steps to replace the casters on an office chair to ensure safety and proper functionality:

1. Identify the Caster Type Turn the chair upside down steadily and observe how the casters are attached to the chair legs:

• Snap-ring casters: There is a circular groove at the top of the caster stem. When pressed, it makes a clicking sound. They are commonly found in plastic or metal stem structures.
• Threaded casters: The caster stem has visible external threads, similar to a screw, and requires rotation for removal.
• Stem casters: They have no special structure and are directly fixed by a stem, mostly made of hard plastic or metal.

2. Remove the Old Casters Select tools and methods according to the caster type:

• Snap-ring casters: Insert a screwdriver or a flat tool into the gap between the caster stem and the chair leg. Gently pry the snap-ring position. After hearing a click, pull it out vertically. If the caster separates from the stem, use needle-nose pliers to grip the upper part of the ring as a fulcrum and pry it open.
• Threaded casters: Use a 6-inch adjustable wrench to grip the base of the caster stem and rotate it counterclockwise at a 45-degree angle to the ground. If it is severely rusted, spray a small amount of WD-40 lubricant first. You can also use needle-nose pliers to pry between the casters for assistance in removal.
• Stem casters: Pull them out vertically directly. If there is a lot of resistance, insert a flat-head screwdriver into the gap to pry, or use pliers to grip the stem and tap it lightly with a hammer.

3. Install the New Casters Make sure the new casters match the chair legs before operating:

• Snap-ring casters: Align them with the chair leg sockets and press vertically. A click sound indicates that they are installed in place.
• Threaded casters: Rotate them clockwise until they are fully tightened to prevent loosening.
• Stem casters: Align them with the holes and press them in directly. If installation is difficult, rotate them clockwise while pressing, or sit on the chair and use your body weight to press them in.

4. Test and Acceptance Push the chair to slide on a tiled floor and check the following indicators:

• Noise: It should be lower than 45 decibels with no obvious friction sound.
• Smoothness: It should roll continuously for 10 meters without jamming or deviation.

Precautions

• Material selection: For hard floors (wooden floors/tiles), choose PU casters to reduce scratches. For carpets, use nylon casters to enhance grip.
• Size matching: The common stem diameter is Φ11mm. An error of more than 0.2mm will lead to unstable installation, and you need to replace them with suitable casters.
• Emergency handling: If the interface does not match, you can sand the metal stem or wrap it with Teflon tape to increase the diameter (only for temporary use. For long-term use, replace the parts).

It is recommended to wear gloves during operation to avoid scratches. If the casters are severely rusted, apply lubricant and let it sit for 10 minutes before removal.