How can we quickly determine if a caster is rusted?

To quickly determine if a caster is rusted, you need to combine visual, tactile, and functional testing, focusing on the condition of the metal components.

1. Visual Inspection
Directly inspect areas such as the bracket welds, shaft, bearings, and the inside of the rim. Early rust appears as light yellow spots; mid-stage rust appears as reddish-brown patches; severe rust appears as large areas of redness, flaking, or chipping.

2. Physical Testing
Wipe the metal surface with a dry cloth. If a brownish-red powder remains or feels rough, rust is present. Lightly scrape the suspected area with your fingernail. If rust powder falls off or the underlying rust color becomes visible, rust is confirmed.

3. Functional Testing
Turn the caster. If there is a sticking sound, an unusual noise (such as a creaking sound), or noticeable resistance, the bearing or axle may be rusted. Gently shake the wheel. If there is excessive play, a grinding sound, or the wheel tilts, rust has caused the structure to become loose.

4. Environmental Considerations
If the caster is exposed to damp, water-rich, or corrosive environments and lacks maintenance, the risk of rust is extremely high. Compare it to a new caster; if it rotates poorly or has a dull surface, it may be rusted.

In summary: First observe the rust → Wipe and verify → Test for smooth rotation → Then, consider the environment. Any abnormalities must be addressed promptly to prevent further damage.