If you searched for a 12 volt round electromagnet or a 120 volt round electromagnet, the real question is not whether the catalog headline says 11 lb. The real question is what remains after air gap, surface quality, load direction, duty strategy, and safety margin are applied. This page gives the tool first, then the evidence and family comparison that makes the answer usable.
Canonical route for 12 volt round electromagnet and 120 volt round electromagnet intent. No duplicate alias page is needed because the selection logic is one clustered decision.
Fourteen public sources were screened in this pass, including Eclipse (January 2025 v2), Kendrion technical notes, Schmalz operating instructions (09/2020), Kanetec lifting-magnet catalog data, 120 VAC / 110 VDC round-magnet product pages, OSHA 1910.179, ASME B30.20/BTH-1 scope pages, and USDA guidance citing ANSI C84.1 service-voltage ranges.
Small 12 V reference
11.5 lb at zero gap
First real penalty
4.6 lb at 0.09 mm
Shear warning
20-33% of hold force
Default inputs are set to an 11.5 lb, 12 V, small round electromagnet class. Run the checker to see how quickly usable load shrinks once air gap, surface quality, direction, and safety margin are applied. If your RFQ says 120 V, keep the result in boundary mode until the supplier confirms whether the model is 120 VAC or 110 VDC.
Public 12 V small-class reference
11.5 lb
Eclipse 20 mm M52180 at zero air gap
Same class at 0.09 mm gap
4.6 lb
Before any safety factor is applied
Short answer: treat headline force as a best-case steel-face result, not a safe working load. The 12 V public curve gives a usable baseline, and the 120 V alias is handled through explicit AC/DC branch logic on this same canonical URL.
Key number
114-126 V
USDA guidance citing ANSI C84.1-2016 shows 120 V service is a window under normal Range A conditions. Validate hold and release behavior at voltage edges, not just at nominal 120 V.
Key number
120VAC / 110VDC
Industrial Magnetics publishes round electromagnets in both 120 VAC and 110 VDC classes. Magnetool’s 120 VAC notes add release and residual-force boundaries that do not appear in simple 12 V headline checks.
Key number
5.2 kg / 11.5 lb
The closest public small 12 V example reviewed here is Eclipse M52180/12VDC: 20 mm diameter, 100% ED, 210 mA, and 5.2 kg holding force at zero air gap.
Key number
-60% at 0.09 mm
That same Eclipse magnet drops from 5.2 kg to 2.1 kg at just 0.09 mm gap before any safety factor is applied.
Key number
20-33%
Kendrion publishes shifting force at only about 20-33% of holding force, so any sideways slip risk destroys the headline number quickly.
Key number
20-40%
Kendrion technical notes state residual holding force after deactivation can be around 20-40% depending on the workpiece, so release behavior must be validated.
| Question | Short answer | Why it matters |
|---|---|---|
| What is a 12 volt round electromagnet? | In public catalog terms it is a small energise-to-hold magnet class, not a certified lifting magnet. The closest reviewed example is a 20 mm 12 V part rated at 5.2 kg / 11.5 lb under zero-gap test conditions. | The phrase sounds like a lifting device, but the published product class is really about static holding force on a steel coupon. |
| What does “120 volt round electromagnet” usually imply? | Usually a mains-powered branch (120 VAC round models or 110 VDC round models), not the same evidence baseline as the 12 V small-magnet proxy. | If 12 V, 110 VDC, and 120 VAC are treated as interchangeable labels, release behavior and coil-selection decisions become unreliable. |
| What voltage window should a 120V branch be checked against? | For 60 Hz systems, USDA guidance citing ANSI C84.1 shows Range A service at 114-126 V, with wider Range B tolerated only for limited duration. | If validation happens only at nominal 120 V, low-line or high-line behavior can still fail during production. |
| Can it safely lift 11 lb in the real world? | Usually no. The same 20 mm class falls to 2.1 kg / 4.6 lb at 0.09 mm gap before any safety factor or surface derating is applied. | Paint, plating, rust, and poor flatness create exactly the kind of gap that makes field performance disappoint. |
| Does 12 V automatically mean continuous safe hold? | No. Voltage tells you the electrical class; it does not choose the right magnet family for long hold-open duty, power-fail-safe holding, or lifting. | You still need to decide between electro holding, permanent electro, door magnets, or purpose-built lifting magnets. |
| What if the load can slide sideways? | Treat that as a different problem. Kendrion publishes shifting force at only about 20-33% of the holding-force value. | A magnet that looks adequate on pull-off can still lose the part in shear without a mechanical stop. |
| When should I reject the small holding-magnet idea entirely? | Reject it for overhead lifting, pick-and-place WLL work, power-fail-safe retention, or door hold-open projects. | Those use cases point to different product families with different published proof and safety logic. |
| When does this become a compliance-gated lifting decision? | As soon as the use case is below-the-hook or overhead lifting, force screening alone is not enough. | OSHA 1910.179 and ASME B30.20/BTH-1 introduce control-circuit, marking, inspection, and testing requirements. |
| Can “power off” still leave the part stuck briefly? | Yes. Kendrion technical guidance says residual force after deactivation can remain at roughly 20-40% depending on the workpiece. | If your process needs clean, fast release, add a release check instead of assuming force goes to zero immediately. |
Fixture designers, automation engineers, and buyers comparing small 12 V hold magnets on clean ferromagnetic parts.
Anyone who really needs a power-fail-safe latch, fire-door hardware, certified pick-and-place WLL, or overhead lifting approval.
The alias is merged into this canonical URL, but the decision path still branches by coil class. This table prevents AC/DC voltage terms from being mistaken for one interchangeable dataset.
Decision visual
The user intent is still round-electromagnet fit, so the URL stays canonical. What changes is the evidence branch: 12 V proxy screening, 120 VAC release-risk branch, or 110 VDC higher-voltage branch.
| Search phrasing | Published signal | What it usually means | Boundary before RFQ |
|---|---|---|---|
| 12 volt round electromagnet | Eclipse M52180/12VDC publishes 5.2 kg (11.5 lb) zero-gap holding force with a 12 V, 210 mA, 100% ED reference. Source: Eclipse Magnetics M52xxx datasheet (January 2025 v2) | Compact DC energise-to-hold screening with strong dependence on gap and contact quality. | Use 12 V curve logic for first-pass screening, then verify on the exact steel face and duty cycle. |
| 120 volt round electromagnet (AC branch) | Industrial Magnetics publishes 120 VAC round models. Magnetool states its 120 VAC line is internally rectified to 110 VDC, can retain up to 20% residual magnetism without release pulse, and does not support electronic release via the built-in rectifier path. Source: Industrial Magnetics: round electromagnets (24VDC, 110VDC, 120VAC); Magnetool: 120 V.A.C. electromagnets (updated Nov 2025); USDA RUS Bulletin 1724D-114 (Dec 2017, cites ANSI C84.1-2016) | Facility-power holding branch where supply-voltage window and release behavior must both be verified. | Confirm 120 VAC coil class, clean-release method, and low/high-line behavior (normal service window 114-126 V) before approval. |
| 120 volt round electromagnet (DC branch) | Industrial Magnetics lists 110 VDC round options. Magnetool round lifting models also list 110 VDC variants with published lifting capacities and explicit 2:1 safety-factor ratings. Source: Industrial Magnetics: round electromagnets (24VDC, 110VDC, 120VAC); Magnetool: round lifting magnets (110 VDC, 2:1 safety-factor ratings) | Higher-voltage DC holding or lifting path, typically outside compact 12 V proxy assumptions. | Request voltage-specific pull/lift basis, duty rating, and safety-factor method before RFQ. |
This fills a core stage1b gap: 120 V intent needs both electrical-window checks and regulatory routing when the use case approaches overhead lifting.
Power boundary visual
A 120 V keyword does not lock operation to one exact electrical condition. Treat low-line and high-line service behavior as separate checks, especially when release timing is safety-critical.
| Operating basis | Published window or constraint | Decision action |
|---|---|---|
| ANSI C84.1 Range A (60 Hz, 120 V class) | Service: 114-126 V; utilization: 108-127 V. Source: USDA RUS Bulletin 1724D-114 (Dec 2017, cites ANSI C84.1-2016) | Validate holding and release behavior at low-line and high-line conditions, not only at nominal 120 V bench tests. |
| ANSI C84.1 Range B (tolerable, limited duration) | Service: 110-127 V; utilization: 104-127 V. Source: USDA RUS Bulletin 1724D-114 (Dec 2017, cites ANSI C84.1-2016) | Range B is a temporary tolerance zone. Treat sustained operation there as a boundary case requiring thermal and release checks. |
| 120 VAC internal-rectifier branch | Magnetool states 120 VAC input is internally rectified to 110 VDC; up to 20% residual magnetism can remain without release pulse. Source: Magnetool: 120 V.A.C. electromagnets (updated Nov 2025) | Do not assume clean electronic release on every power-off event. Verify release method and de-energized behavior on the production part. |
| Trigger | Published requirement | Required action |
|---|---|---|
| Use case shifts to below-the-hook or overhead lifting | ASME B30.20 governs marking, construction, installation, inspection, testing, maintenance, and operation; ASME BTH-1 provides minimum structural/mechanical/electrical design criteria. Source: ASME B30.20 (2025): below-the-hook lifting devices; ASME BTH-1 (2023): design of below-the-hook lifting devices | Exit force-only screening and move into a lifting-device compliance workflow before approval. |
| Crane-mounted lifting magnet control circuit | OSHA 1910.179(g)(5)(iii)-(iv): provide a lockable means to open the magnet circuit and a means to dissipate inductive load. Source: OSHA 29 CFR 1910.179 overhead and gantry cranes | Review control architecture and release path in drawings before procurement. |
| Commissioning new or altered lifting installation | OSHA 1910.179(k)(2): test to rated load and not less than 125% of rated load, with test reports filed where readily available. Source: OSHA 29 CFR 1910.179 overhead and gantry cranes | Require commissioning test records; reject approvals based on catalog pull alone. |
| Electrical exposure to dirt, oil, or moisture | OSHA 1910.179(g)(2)(ii): crane electrical equipment shall be protected from dirt, grease, oil, and moisture. Source: OSHA 29 CFR 1910.179 overhead and gantry cranes | Confirm enclosure/wiring protection for the operating environment before sign-off. |
Most selection errors come from treating every magnet that can stick to steel as the same product category. The published evidence says otherwise.
Decision map
Stay with a plain electro holding magnet only when the job is static holding on a known steel face and the release on power loss is acceptable. Move families as soon as you need fail safe behavior, door hardware logic, or a real lift rating.
| Family | Best for | Published signals | Not for |
|---|---|---|---|
| Electro holding magnet | Static clamping or holding on clean steel faces | Kendrion publishes 36-30,000 N, 12/24 V, and 100% ED. Source: Kendrion: electro holding magnets | Power-fail-safe hold, overhead lifting, or dynamic pick-and-place. |
| Permanent electro holding magnet | Low-energy hold or safe hold during power failure | Kendrion publishes currentless holding force, safe holding during power failure, and 8-3,500 N force range. Source: Kendrion: permanent electro holding magnets | Generic plug-and-play swaps where release pulse design is unknown. |
| Door holding magnet | Door hold-open systems and release hardware | Kendrion publishes 24 V DC, 300-1,568 N, and EN1155 / EN14637 context. Source: Kendrion: door holding magnets | Part clamping or steel-pick applications. |
| Magnetic gripper or lifter family | Pick-and-place or applications needing a 3:1 WLL mindset | Schmalz designs around a 3 safety factor, and Eclipse points pick-and-place toward dedicated families. Source: Schmalz magnetic gripper operating instructions (09/2020) | The cheapest small round magnet swap-in. |
| Purpose-built lifting magnet | Real lifted-load applications | Kanetec publishes separate lift capacity and says lift is half of holding power. Source: Kanetec catalog 098: lifting electromagnets | Assuming a small 11 lb hold magnet is “close enough” to a lifting system. |
This section is the 12 V baseline evidence layer. For 120 V alias intent, use this as directional logic only and branch to the voltage-class table before supplier decisions.
Encoded SVG chart
The public 20 mm curve is useful because it is already in the same order of magnitude as the 11 lb search phrasing. It shows why a “small air gap” is not a small penalty on a small round holding magnet.
| Air gap (mm) | Hold (kg) | Hold (lb) | Relative to zero gap |
|---|---|---|---|
| 0.00 | 5.20 | 11.46 | 100% |
| 0.09 | 2.10 | 4.63 | 40% |
| 0.18 | 0.90 | 1.98 | 17% |
| 0.27 | 0.45 | 0.99 | 9% |
| 0.36 | 0.30 | 0.66 | 6% |
| 0.59 | 0.20 | 0.44 | 4% |
| 1.00 | 0.10 | 0.22 | 2% |
Context note: this is a specific public 20 mm / 12 V magnet. Use it as a small-class proxy, not as a substitute for the exact supplier curve of your selected part number.
The checker does not pretend to know your hidden supplier data. It intentionally uses public facts where they exist, then makes its own assumptions visible instead of hiding them.
Flow
The sequence is simple: start with the catalog holding force, apply gap loss, apply real-contact and direction derating, divide by a safety factor, then ask if the use case actually belongs to another family.
| Stage | Public evidence used here | Still unknown until you test or ask |
|---|---|---|
| 1. Start with published holding force | Use the supplier’s normal holding-force value, not the weight you hope to lift. | Whether that value came from a polished coupon or the real production part. |
| 2. Apply air-gap loss | The 20 mm Eclipse 12 V curve falls from 5.2 kg at zero gap to 2.1 kg at 0.09 mm. | Your exact part geometry and whether your magnet face behaves better or worse than the proxy. |
| 3. Apply contact and direction loss | Kendrion publishes shifting force at only about 20-33% of holding force. | The real steel chemistry, roughness, plating, and alignment in your assembly. |
| 4. Apply material and residual-force boundaries | Kendrion states force references are tied to material context (such as S235JR) and residual force can remain about 20-40% after deactivation. | Release performance on your exact steel grade, especially if hardened/alloy or if fast release is required. |
| 5. Apply safety margin and family screen | Schmalz uses a 3 safety factor for magnetic gripper design, and Kanetec publishes lift capacity separately from maximum holding power. | Whether the consequence of a dropped part demands a higher margin or a different family entirely. |
| 6. Trigger compliance workflow when lifting scope appears | OSHA 1910.179 and ASME B30.20/BTH-1 define control, testing, and design gates for below-the-hook lifting systems. | Whether your exact installation is classified as overhead lifting and which jurisdictional requirements apply to commissioning records. |
This section records what was missing for the alias intent and what was implemented so the page can pass hybrid-mode quality gates before SEO/GEO finalization.
| Gap | Added evidence | Decision impact | Source |
|---|---|---|---|
| Earlier content did not show the source publication window or recency for the 11 lb / 12 V benchmark. | Pinned the benchmark to Eclipse M52xxx datasheet revision January 2025 v2 with explicit values (5.2 kg, 210 mA, 2.4 W, 100% ED) and air-gap points. | Users can now verify the benchmark date before reusing numbers in 2026 procurement reviews. | Eclipse Magnetics M52xxx datasheet (January 2025 v2) |
| The checker lacked material and ambient boundaries tied to published conditions. | Added explicit guardrails from Kendrion technical explanations: S235JR-style baseline, hardening-permeability penalty risk, and DIN VDE 0580 normal ambient context (-5 to 40 °C duty assumption). | “Looks fine on paper” results are now downgraded to boundary status when material or temperature context is outside published assumptions. | Kendrion: technical explanations PDF |
| Release behavior risk was under-specified for automation use cases. | Added residual-force boundary from Kendrion technical notes (around 20-40% after deactivation, workpiece-dependent). | Users now see that “power off” does not always mean immediate zero force; release validation is treated as a required step. | Kendrion: technical explanations PDF |
| Lift-use rejection lacked a standards-adjacent, product-basis contrast. | Added Kanetec lifting-magnet catalog boundary: lift capacity is rated as half of maximum holding power and can drop with plate thickness/surface conditions. | The page now distinguishes round holding magnets from true lifting systems with a source-backed rule, not wording preference. | Kanetec catalog 098: lifting electromagnets |
| Tool assumptions did not explicitly block non-ferromagnetic workpieces. | Added Schmalz operating-rule boundary: magnetic grippers are intended for ferromagnetic workpieces and designed with S=3 safety-factor logic. | The checker now returns a no-go path for non-ferromagnetic parts and preserves a conservative safety baseline for pick-and-place style scenarios. | Schmalz magnetic gripper operating instructions (09/2020) |
| The alias phrase “120 volt round electromagnet” had no explicit AC/DC split with published sources. | Added manufacturer evidence showing round-magnet voltage classes (120 VAC and 110 VDC) and the 120 VAC residual-force/release boundary. | Visitors with 120V intent now get a direct branch: treat 12V proxy output as directional until voltage-class-specific data is confirmed. | Magnetool: 120 V.A.C. electromagnets (updated Nov 2025) |
| 120V branch still lacked a published service-voltage window and tolerance boundaries. | Added USDA RUS guidance citing ANSI C84.1-2016 for 60 Hz systems: 120 V Range A service 114-126 V, Range B service 110-127 V (limited-duration tolerance). | 120V decisions now require low-line/high-line validation instead of single-point 120 V assumptions. | USDA RUS Bulletin 1724D-114 (Dec 2017, cites ANSI C84.1-2016) |
| 120 VAC release behavior was not tied to explicit product-family constraints. | Added Magnetool 120 VAC evidence: internal rectification to 110 VDC, no built-in electronic release path, and residual magnetism risk up to 20% without release pulse. | RFQ decisions now include release-method checks and mechanical-assist fallback instead of force-only screening. | Magnetool: 120 V.A.C. electromagnets (updated Nov 2025) |
| Overhead-lifting escalation path was missing regulatory and standards gate language. | Added OSHA 1910.179 gate: rated-load marking/testing path, lockable magnet-circuit opening, and induced-voltage dissipation requirements. | Force-only decisions are now blocked when the use case enters crane-lifting workflow. | OSHA 29 CFR 1910.179 overhead and gantry cranes |
| Below-the-hook standard scope was not linked to a clear decision boundary. | Added ASME B30.20 and BTH-1 references so users can separate simple holding use from below-the-hook lifting-device design and operation requirements. | When lifting scope appears, the page now routes to standards-first review instead of generic catalog comparison. | ASME B30.20 (2025): below-the-hook lifting devices |
| Trigger | Why this blocks | Required action |
|---|---|---|
| Workpiece is non-ferromagnetic | Force estimates from steel-based curves are invalid on non-ferromagnetic parts. Source: Schmalz magnetic gripper operating instructions (09/2020) | Move to mechanical clamp, vacuum, adhesive, or redesign with a ferromagnetic interface. |
| Ambient or duty context outside normal -5 to 40 °C assumptions | Published continuous-duty context no longer matches thermal conditions. Source: Kendrion: technical explanations PDF | Run part-level thermal and force validation before approving the selection. |
| Shear/sliding load without mechanical stop | Shifting force can be only 20-33% of nominal holding force. Source: Kendrion: technical explanations PDF | Add a hard mechanical stop or redesign so load direction is normal pull. |
| Use case is actual lifting, not static holding | Lifting systems use a different rating basis (lift capacity, not only holding force). Source: Kanetec catalog 098: lifting electromagnets | Use a purpose-built lifting magnet family with published lift-capacity basis. |
| 120 V service operates near low-line or high-line limits | ANSI C84.1 service windows show 120 V systems can run across a range, not a single fixed point. Source: USDA RUS Bulletin 1724D-114 (Dec 2017, cites ANSI C84.1-2016) | Validate hold and release behavior at both low-line and high-line service conditions before approval. |
| Selection expands to below-the-hook overhead lifting | This is no longer a generic holding-magnet decision; OSHA/ASME compliance gates apply. Source: OSHA 29 CFR 1910.179 overhead and gantry cranes | Route the project to B30.20/BTH-1 + OSHA 1910.179 review with documented testing and control-circuit checks. |
| Claim | Evidence status | Next action |
|---|---|---|
| Universal derating factor for painted or oxidized steel across all 12 V round magnets | Pending confirmation (待确认): no single, cross-brand public curve set was found for this geometry and coating class. | Request part-level pull data on your real coated steel and update this page when comparable public curves appear. |
| Public fatigue-cycle life curves for 11 lb-class round magnets under vibration + repeated release | No reliable public dataset found (暂无可靠公开数据) in this pass. | Treat cycle-life claims as supplier-specific until test reports or public endurance curves are available. |
| Single public rule for release time after de-energizing across steel grades | Evidence is material-dependent: Kendrion reports residual-force behavior, but no universal timing curve was verified. | Run release-time validation on the production workpiece and document the measured de-release window. |
| Universal conversion rule from 12 V proxy force curves to all 120 VAC round-electromagnet models | Pending confirmation (待确认): voltage class exists publicly, but no universal cross-brand conversion curve was verified. | Request 120 VAC / 110 VDC model-specific pull-force and release data before using 12 V proxy numbers for procurement decisions. |
| Public low-line/high-line force and release curves across the full ANSI C84.1 120 V service window | No reliable public cross-brand dataset found (暂无可靠公开数据) for 114-126 V performance drift on round-electromagnet models. | Require supplier validation across the intended service-voltage range and archive the measured hold/release results in the RFQ file. |
This is not a price table. It is a proof-model table. Each row explains what that published product family tells you about the round-electromagnet decision.
| Reference | Family | Published data | What it proves |
|---|---|---|---|
| Eclipse M52180/12VDC | Small energise-to-hold magnet | Revision January 2025 v2: 5.2 kg hold, 12 V, 210 mA, 2.4 W, 100% ED | This is what an 11 lb / 12 V class product actually looks like in a public datasheet. |
| Kendrion technical explanations | Holding-force behavior model | Shifting force 20-33%; residual force after deactivation around 20-40%; material baseline references include S235JR | Material, release behavior, and load direction are first-order boundaries, not optional fine tuning. |
| Kendrion GTB electro holding range | Industrial electro holding magnet | 36-30,000 N, 12/24 V, 100% ED | Industrial holding magnets exist well above hobby scale, but still assume proper armature and no unsupported gap. |
| Kendrion PEM permanent electro range | Permanent electro holding magnet | 8-3,500 N, currentless holding force, 25% ED | Power-fail-safe and low-energy hold are a separate family decision. |
| Kendrion door holding range | Door hold-open magnet | 24 V DC, 300-1,568 N, EN1155 / EN14637 context | Door hardware is not the same selection problem as small part holding. |
| Schmalz magnetic gripper instructions | Magnetic handling rule set | Operating guide 09/2020: ferromagnetic-only workpieces and safety factor S=3 for horizontal transport | Tool output must block non-ferromagnetic parts and keep conservative working-load assumptions. |
| Kanetec LMU-UW lifting electromagnet | Purpose-built lifting magnet | Lift capacity rated as half of maximum holding power; smallest listed capacity 600 kg; plate-thickness condition notes included | Real lifting systems publish lift ratings and backup logic instead of only quoting holding force. |
| Industrial Magnetics round electromagnet page | Voltage-class catalog boundary | Round electromagnets listed in 24 VDC, 110 VDC, and 120 VAC configurations with model-level WLL values. | Voltage class and working-load language are published as distinct procurement fields, not interchangeable labels. |
| Magnetool 120 V.A.C. electromagnets | 120 VAC release behavior boundary | 120 VAC input internally rectified to 110 VDC; residual magnetism up to 20% without release pulse; built-in path does not provide electronic release function. | For AC branch decisions, release behavior must be validated explicitly instead of inferred from nominal voltage. |
| USDA RUS Bulletin 1724D-114 / ANSI C84.1-2016 | Service-voltage boundary for 120 V systems | 60 Hz 120 V class windows include Range A service 114-126 V and Range B service 110-127 V (limited duration). | “120 V” is an operating range, so hold/release checks need edge-voltage validation. |
| OSHA 1910.179 + ASME B30.20/BTH-1 | Below-the-hook lifting governance | OSHA defines magnet controls/testing expectations; ASME B30.20 and BTH-1 define operation and design framework for below-the-hook devices. | Once use case becomes overhead lifting, compliance evidence is mandatory before quote or installation approval. |
The point of this section is not to scare the user away from holding magnets. The point is to make the predictable failure modes visible before someone orders the wrong family.
| Risk | Impact | What public evidence says | Mitigation |
|---|---|---|---|
| Treating 120V intent as interchangeable with 12V proxy math | High | Industrial Magnetics publishes separate 120 VAC and 110 VDC round models, and Magnetool documents residual-force behavior specific to 120 VAC round designs. | Branch the review by coil class first, then apply model-specific pull and release data before approval. |
| Using nominal 120 V as a fixed value instead of a service window | Medium | USDA guidance citing ANSI C84.1-2016 shows 120 V service can operate across 114-126 V (Range A), with wider Range B tolerated for limited duration. | Test hold and release behavior at low-line and high-line service conditions before sign-off. |
| Assuming built-in rectified 120 VAC models always release cleanly | High | Magnetool states 120 VAC units are internally rectified to 110 VDC, do not provide electronic release through the built-in rectifier path, and may retain up to 20% residual magnetism. | Specify release method in RFQ and verify de-energized release behavior on the production workpiece. |
| Treating catalog force as lifted weight | High | The Eclipse 20 mm example loses about 60% at 0.09 mm gap, and Kanetec halves holding power to publish lift capacity on lifting magnets. | Use the checker, then verify the real working load on the production steel face before approval. |
| Shear or vibration | High | Kendrion publishes shifting force at 20-33% of holding force. | Add a mechanical stop or redesign so the magnet sees a normal pull-off load instead of a sliding load. |
| Unexpected release lag after power-off | Medium | Kendrion technical notes indicate residual force after deactivation can remain around 20-40% depending on the workpiece. | Validate release behavior on the real part and add an active separation strategy when fast release is required. |
| Power outage releases the load | High | Standard energise-to-hold magnets release when power is removed, while permanent electro ranges publish safe holding during power failure. | Move to a permanent electro family or add a mechanical fail-safe. |
| Material mismatch versus published baseline | High | Kendrion ties reference force values to specific steel conditions (for example S235JR) and warns hardening can reduce permeability. | Treat unknown/hardened materials as boundary cases and require part-level testing before sign-off. |
| Long continuous hold outside thermal assumptions | Medium | Eclipse recommends energise-to-release magnets for long continuous powering; Kendrion cites normal duty assumptions around -5 to 40 °C. | Switch families for long hold duty or validate thermal behavior under real ambient conditions. |
| Wrong product family for the job | High | Door magnets, holding magnets, magnetic grippers, and lifting magnets publish different proof, voltages, and safety logic. | Use the family-comparison table before asking suppliers for price or lead time. |
| Treating overhead lifting as a normal fixture-hold decision | High | OSHA 1910.179 and ASME B30.20/BTH-1 place crane-lifting magnets under specific control, testing, and design frameworks. | Trigger compliance review (rated-load testing, control-circuit checks, and standards traceability) before procurement. |
One visual summary
The tool can screen force, but the report layer matters because the biggest errors happen when buyers compare holding magnets against door magnets or lifting magnets as if they are interchangeable SKUs. They are not.
Fast rule
If a dropped part would be unsafe, if power loss cannot release the load, or if the part slides instead of pulling off normally, do not approve the small holding magnet from headline force alone.
| Scenario | Inputs | Checker reading | Conclusion |
|---|---|---|---|
| Bench fixture on flat steel coupon | 11 lb catalog force, 0.00 mm gap, flat steel, direct pull, 1.5 lb target | About 3.7 lb conservative working load after a 3:1 safety factor | Reasonable place to prototype a simple holding magnet if dropped parts are low consequence. |
| Painted panel retention | 11 lb catalog force, 0.18 mm gap, painted steel, direct pull, 2.0 lb target | Roughly 0.3 lb working load equivalent after derating | Fails quickly because paint plus gap destroys the small-magnet headline. |
| Sliding steel tag in automation | 11 lb catalog force, 0.09 mm gap, clean steel, shear load, 1.0 lb target | About 0.3 lb working load equivalent after shear derating | Not acceptable without a mechanical stop; the sliding condition is the real blocker. |
| Long hold-open duty with power-loss concern | 11 lb class magnet, 3.0 hour hold time, release on outage not allowed | Force may exist, but family choice changes to permanent electro or door magnet | This is no longer a small electro holding magnet decision at all. |
| 120 VAC branch with low-line supply and release-critical timing | 120 VAC request, service may vary across 114-126 V, clean release required after de-energizing | Boundary status: nominal-force math is insufficient until low/high-line release behavior is validated on the actual workpiece | Use 120 VAC model data plus release-test evidence; do not approve from nominal 120 V label alone. |
| Plant request says “120 volt round electromagnet” with unknown coil class | 120 V request, 0.09 mm gap estimate, static hold target, AC/DC class not confirmed | Boundary status: force estimate is directional only until 120 VAC or 110 VDC model data is confirmed | Do not release RFQ on keyword alone. Confirm coil class, release behavior, and voltage-specific pull data first. |
Secondary CTA
Send your part material, target load, expected air gap, and load direction. We will flag boundary risks before you commit to a round-electromagnet family.
These are grouped by decision intent rather than glossary trivia so the FAQ section still helps a technical buyer move forward.
The fastest way to waste time on round electromagnets is to request quotes before you know the family, the air-gap basis, or the fail-safe requirement. Use this page to narrow the problem first.
Main CTA
Send the exact part number, target load, steel face condition, gap estimate, and whether power-fail-safe hold is required. That is enough to tell whether you need a holding magnet, a permanent electro family, or something closer to a lifting system.
Reviewed April 12, 2026