When comparing two caster wheels that look identical, the biggest difference is often hidden in the wheel's "core". A thick cast-iron core and a thin pressed-steel core perform very differently under heavy loads.
Cast-Iron Core vs Thin Pressed Core
A thin pressed core is formed from thin sheet steel. It is light and cheap, but under heavy loads or repeated impacts it deforms, twists or makes the wheel tilt, causing bearings to fail early.
A 5.5 mm thick cast-iron core has much thicker, stronger steel, so it keeps its shape even under high loads — the wheel doesn't deform, runs true and extends bearing life.
| Factor | 5.5 mm thick cast core | Thin pressed core |
|---|---|---|
| Load capacity | High (350 kg / wheel) | Limited |
| Deformation | No deformation | Deforms under heavy load |
| Bearing life | Long | Shorter |
| Price | Slightly higher | Cheaper |
Summary
If your work involves pushing heavy loads regularly, don't just look at the wheel size or tread — ask about the "steel core thickness" too, because that decides whether a wheel really lasts or fails quickly.