Spare Office Chair Casters: Small Parts, Big Impact – A Complete Guide to Selection and Replacement

In daily office life, we often overlook those "unassuming yet crucial" details – such as the five small casters under an office chair. They silently shoulder the responsibilities of sliding, steering, and supporting. Once damaged or worn out, they not only hamper work efficiency but may also scratch floors, cause unstable sitting postures, and even create safety hazards. For this reason, keeping a set of spare office chair casters on hand is a wise choice for anyone who values office experience and equipment maintenance.

I. Why Do You Need Spare Casters?

Prone to Wear and Tear: After prolonged use, casters may develop cracks, deformation, stuck bearings, or loose stems.

Sudden Breakdowns: A single caster falling off can instantly throw the chair off balance, disrupting normal use.

Upgrade Needs: Stock casters may be noisy or damaging to floors; replacing them with high-quality, quieter, smoother alternatives is a great improvement.

Cost-Effective: A set of premium spare casters usually costs only ¥20–¥80, far less than replacing an entire chair.

Emergency Readiness: Having a spare set at home or in the office eliminates the need for last-minute searches and purchases, saving time and effort.

II. How to Choose the Right Spare Casters?

Not all casters are universal. Focus on these key parameters when purchasing:

Stem SizeThis is the core of compatibility! Over 90% of modern office chairs use stem casters, with common specifications:

7/16 inch (approx. 11mm) in diameter × 7/8 inch (approx. 22mm) in length – the most mainstream standard.

A small number of lightweight chairs use 5/16 inch (approx. 8mm) stems.

✅ Recommendation: Remove an old caster and measure the stem’s diameter and length with a caliper, or check the chair’s instruction manual/brand official website.

Caster Material

Polyurethane (PU) Casters: Soft, quiet, and floor-friendly (ideal for wooden floors and tiles) – highly recommended for home and office use.

Nylon Casters: Hard-wearing with strong load capacity, suitable for carpeted environments but noisy on hard floors.

Rubber-Coated Casters: Offer good grip but tend to age quickly and leave marks; they have been gradually replaced by PU casters.