A lifting magnet that will not release a load, will not pick one up, or has lost part of its holding strength is not just an inconvenience, it stops production and puts the load and the operator at risk. Most magnet failures fall into three categories: demagnetization, physical damage, and corrosion or contamination. Here is what causes each one, what to check first, and when to call a technician instead of troubleshooting it yourself.
Quick Reference: Which Magnet Issue Am I Seeing?
Not sure which of the three issues below matches what you are seeing? Use this table as a starting point, then confirm with a technician before deciding on repair or replacement.
| Issue | Common Symptom | Likely Cause | Repair or Replace? |
|---|---|---|---|
| Demagnetization | Magnet activates but will not hold rated load, or fails a test lift | Heat exposure, physical shock, or normal age/duty cycle wear | Often repairable (re-magnetization or coil service); replace if the core or coil is structurally degraded |
| Physical Damage | Visible cracks, chips, or a damaged housing or mounting point | Dropped loads, impacts against structural steel, rough handling | Repairable if housing and mounting points are structurally sound; replace if structural damage is confirmed |
| Corrosion / Contamination | Surface rust, debris buildup on the pole face, seal wear | Outdoor or wash-down environments, contaminated pole face | Repairable early (clean, recoat, reseal); replace if corrosion has reached the coil |
Issue 1: Demagnetization and Weak Holding Strength
Demagnetization is the most common complaint we see on lifting magnets: the magnet still activates, but it no longer holds the rated load. It is usually caused by one of three things.
- Heat exposure. Magnets used near furnaces, welding operations, or hot scrap lose strength permanently once they cross their material’s Curie-adjacent temperature threshold. This is common in scrap and primary metals environments.
- Physical shock. Repeated dropping, impacting, or slamming a magnet down on a load knocks the internal domains out of alignment over time.
- Age and duty cycle. Even in normal service, magnets lose a small percentage of strength every year; a magnet running multiple shifts a day will show measurable loss faster than one running occasionally.
What to check first: compare current lift capacity against the rated capacity on the nameplate using a known test load. If it is holding meaningfully under rated capacity, do not keep running it at full rated loads. Book a magnet inspection so the loss is quantified and documented rather than guessed at.
How CRANE 1 fixes it: our technicians test actual holding force against nameplate rating, and where the coil or core has usable life left, we can often restore strength through re-magnetization or coil service rather than replacing the unit outright. Where the loss is structural, we handle full magnet refurbishment or replacement as part of our below-the-hook lifter services.
Issue 2: Physical Damage – Cracks, Chips, and Broken Housings
Lifting magnets take a beating: dropped loads, impacts against structural steel, and years of contact with rough scrap or stock all add up.
- Cracks usually start at stress points and get worse under repeated loading; a cracked housing is a structural failure risk, not a cosmetic one.
- Chips at the face reduce the contact area against the load, which reduces effective holding force even if the magnet still “works.”
- Broken housings or mounting points are a stop-work issue: an inspection is required before the magnet goes back into service.
What to check first: a visual inspection of the housing, face, and mounting/shackle points before every shift is enough to catch most of this early, per your existing inspection program.
How CRANE 1 fixes it: our field technicians assess whether a cracked or chipped magnet can be safely repaired (housing weld repair, face resurfacing) or needs replacement, and we carry this out as part of scheduled maintenance visits or emergency service calls.
Issue 3: Corrosion, Rust, and Contamination
Magnets that run outdoors, near coolant, or in wash-down environments are prone to corrosion on the housing and face, and contamination (metal fines, debris) building up on the pole faces.
- Surface rust on the housing is mostly cosmetic early on, but left unaddressed it spreads to electrical connections and seals.
- Face contamination reduces the direct metal-to-metal contact the magnet needs for full holding force, the same way a dirty electrical contact reduces conductivity.
- Coating and seal breakdown lets moisture into the coil, which is the failure path that actually takes a magnet out of service.
What to check first: keep the pole face clean between uses, and inspect seals and coating condition on any magnet used outdoors or in wash-down areas.
How CRANE 1 fixes it: we clean and recoat housings, replace worn seals, and where corrosion has reached the coil, handle rewinding or full unit replacement, all documented as part of your inspection and asset management records.
Keep Your Lifting Magnets at Full Strength
A magnet that is quietly losing strength is a production risk that usually goes unnoticed until it fails on a load. CRANE 1 inspects, repairs, and refurbishes lifting magnets of all types as part of our below-the-hook services, backed by the same 24/7/365 emergency response we provide for cranes and hoists.
Schedule a Magnet Inspection | Call 855-24CRANE
Frequently Asked Questions
How do I know if my lifting magnet needs repair instead of replacement?
If the housing and coil are structurally sound and the loss of strength is within a repairable range, re-magnetization or coil service is usually the more cost-effective path. A technician can confirm this with a load test rather than a visual estimate.
How often should lifting magnets be inspected?
Frequency depends on duty cycle and environment (high-heat and high-cycle applications need more frequent checks), but every lifting magnet should be part of a documented periodic inspection program, the same way hooks and hoists are.
Can a demagnetized magnet be restored to full strength?
In many cases yes, if the core and coil have not suffered permanent structural damage. This is something to have tested rather than assumed. For more information, contact Crane 1 Services today.