How to determine whether the bearings of metal casters need to be replaced?

Metal Caster Bearing Replacement Guide

Core Judgment Criteria (Replacement is indicated if any of the following occur):

Obvious Noise: A continuous "squeaking," "rubbing," or "ball-smashing" noise is heard during rotation, increasing with speed and becoming irregular and harsh. The noise persists even after proper lubrication.

Large Stuttering or Resistance: A noticeable stuttering sensation (intermittent rotation) or significantly increased initial resistance (over 30% greater effort than a new caster) is felt when pushing. The hand-turned caster body has a "stuck point" or is heavy overall.

Excessive Play: The hand-turned caster body (axial/radial) has noticeable play in the bearing area (>1mm, normal ≤0.5mm), accompanied by a clanging sound.

Detailed Inspection to Aid Judgment:

Appearance: Remove the cover and inspect the raceways and balls for rust, oxidation, foreign matter (grit, debris), or component damage (cracked balls, raceway dents and scratches, or cage fractures).

Lubrication: Abnormal noise or sticking after adding grease, or if the grease turns black or contains metallic particles, indicates severe internal wear.

Applications and Lifespan References:

Industrial Heavy Duty (daily use >8 hours, load >1000kg): Lifespan approximately 6-12 months, replace immediately if abnormalities occur.

Medium-Light Duty (daily use <4 hours, load <500kg): Lifespan approximately 1-2 years, extended if smooth operation occurs, requires regular lubrication.

Harsh Environments (humid, dusty, high temperatures): Fragile bearings require inspections every 1-2 months, and replace immediately if abnormalities occur.

Replacement Necessity:

Continued use of failed bearings can lead to chain reactions such as bracket deformation/weld cracking, increased motor/manpower consumption, equipment vibration, and decreased accuracy.

Summary:

Pay attention to core symptoms such as abnormal noise (ineffective lubrication), sticking, excessive vibration, and rust damage. If any of these symptoms occur, especially if lubrication does not improve, immediately replace the bearing with the same model (preferably a sealed type). Check at least once a month, predict the lifespan based on the scenario, and replace it in advance to reduce costs.