EN 13155 vs. ASME B30.20: A Procurement Guide to Lifting Magnet Safety Standards

For procurement teams and safety engineers operating in heavy industry, sourcing a lifting magnet is no longer a localized transaction. Supply chains are global, steel service centers operate across borders, and manufacturing facilities often transfer equipment between continents. However, when it comes to the safety standards governing magnetic lifting devices, the world is distinctly divided into two primary regulatory frameworks: ASME B30.20 / BTH-1 (North America) and EN 13155 (European Union).

A magnetic lifter that is perfectly legal to operate in a fabrication shop in Texas might fail a health and safety audit in Germany. Conversely, a European-certified magnet might lack the specific documentation required by a US safety inspector applying OSHA’s General Duty Clause.

When a 2-ton steel plate falls from a crane, the immediate tragedy is human. The secondary catastrophe is legal. In the aftermath of a dropped load, inspectors will demand the magnet’s design documentation, proof-test certificates, and maintenance logs. If your procurement process failed to specify the correct standards on the initial Purchase Order (PO), the liability rests squarely on your organization.

In this comprehensive engineering and procurement guide, we will dissect the differences between ASME B30.20 and EN 13155, explore specific mandates like the 3:1 safety factor and the 10-minute backup rule, and provide a strict RFQ checklist to ensure your facility buys certified, compliant lifting systems.

Last reviewed: July 25, 2026.
Scope: Safety standards for non-fixed load lifting attachments, specifically permanent, electro-permanent (EPM), and electro-magnets handling ferrous metals.
Limit: This is a procurement screening guide, not legal advice or a substitute for the current purchased standard, local authority review, or a supplier proof-test certificate.

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1. The Legal Framework: Why These Standards Matter

Before diving into the engineering specifics, it is critical to understand how these standards are enforced. They are not merely suggestions; they form the basis of industrial liability law.

The North American Approach: Consensus Standards and OSHA

In the United States, the Occupational Safety and Health Administration (OSHA) is the federal enforcement body. OSHA standard 29 CFR 1910.179 covers overhead cranes but relies heavily on industry consensus standards for the specifics of below-the-hook devices.

ASME (American Society of Mechanical Engineers) B30.20 is the definitive standard for "Below-the-Hook Lifting Devices." While ASME itself is a non-governmental organization, OSHA routinely cites companies for violating ASME B30.20 under the "General Duty Clause" (Section 5(a)(1) of the OSH Act), which requires employers to provide a workplace free from recognized hazards. Therefore, compliance with ASME B30.20 is a de facto legal requirement in North America.

The European Approach: The Machinery Directive and CE Marking

In the European Union and the wider European Economic Area (EEA), product safety is governed by Directives. The Machinery Directive (2006/42/EC) mandates that all machinery sold or operated in the EU must meet essential health and safety requirements and bear the CE mark.

EN 13155 ("Cranes - Safety - Non-fixed load lifting attachments") is a "harmonized standard." If a lifting magnet complies with EN 13155, it carries a "presumption of conformity" with the Machinery Directive. If a European employer buys a magnet without a valid CE mark and EN 13155 declaration, they are instantly in breach of the law, regardless of whether an accident has occurred.

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2. Deep Dive: ASME B30.20 and ASME BTH-1

When North American buyers issue an RFQ, they typically write: "Must comply with ASME B30.20." However, B30.20 is part of a duo.

• ASME B30.20 covers marking, construction, installation, inspection, testing, maintenance, and operation.
• ASME BTH-1 ("Design of Below-the-Hook Lifting Devices") covers the structural and mechanical engineering calculations.

The 3:1 Design Factor (Safety Factor)

The most famous mandate within the ASME framework for close-proximity lifting magnets is the Design Factor. The standard requires that the lifting magnet possess a breakaway force (the exact amount of pulling force required to tear the magnet off the load) of at least three times (3:1) the rated capacity on the magnet's nameplate.

If a magnet is rated to lift 1,000 kg, it must require at least 3,000 kg of upward force to detach it from a clean, flat, thick, low-carbon steel test block.

Why a 3:1 Factor?

Buyers often ask: "If it can lift 3 tons, why are you artificially limiting me to 1 ton?"

The 3:1 safety factor is not a buffer to let you occasionally overload the crane. It is an engineering necessity to account for real-world variables. In a factory, steel is never perfectly flat, clean, or thick. Rust, scale, paint, air gaps, and the peeling effect on thin plates will drastically reduce the holding power of the magnet. The safety factor ensures that even with these real-world reductions, the magnet holds the load securely.

Inspection and Controls

ASME B30.20 strictly dictates operator interfaces. For instance, battery-operated electromagnets must feature a visible indicator that shows when power is running low, allowing the operator to safely lower the load before the magnetic field collapses.

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3. Deep Dive: EN 13155

EN 13155 takes a slightly different approach. While it also mandates safety factors, it is highly prescriptive regarding the failure modes of powered systems (electromagnets and electro-permanent magnets).

The 10-Minute Power Backup Rule

Perhaps the most crucial requirement in EN 13155 for electromagnets (which rely on continuous electric current to hold the load) is the power failure mandate.

If mains power to the crane is cut, or if the battery dies, an electromagnet will instantly drop its load. EN 13155 requires that mains-fed and battery-fed electromagnets must be equipped with a backup system (usually a UPS and secondary battery bank) capable of holding the nominal load for at least 10 minutes after a power failure. Furthermore, a warning device (optical and acoustic) must immediately alert the operator that main power is lost, giving them a 10-minute window to evacuate the area and lower the load manually.

Note: This is why many modern facilities are transitioning to Electro-Permanent Magnets (EPMs). EPMs use a pulse of electricity only to switch the permanent magnetic field ON or OFF. If power fails during a lift, an EPM will not drop the load. Because they are inherently fail-safe during power loss, EPMs generally bypass the 10-minute battery backup requirement of EN 13155, vastly reducing maintenance costs and TCO.

Two-Action Release Mechanisms

To prevent an operator from accidentally hitting the "release" button and dropping a load mid-air, EN 13155 requires a two-action control system for load release. This usually means the operator must press two buttons simultaneously, or flip a mechanical safety latch before pressing the release button.

Tear-Off (Breakaway) Requirements in EN 13155

For permanent lifting magnets, EN 13155 also requires a safety factor, typically specified as a tear-off force of at least 3 times the working load limit, aligning closely with ASME requirements, though the specific testing conditions and stability calculations differ slightly.

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4. Direct Comparison: ASME B30.20 vs. EN 13155

To assist procurement teams in evaluating supplier data sheets, use this structural comparison table:

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5. The "Fake Certification" Hazard in Procurement

One of the most dangerous traps for a procurement manager is the "Fake CE" or "Self-Certified ASME" claim, frequently seen on ultra-low-cost imported magnets.

How to spot red flags in RFQ responses:

1. No Tear-Off Curves Provided: If a supplier claims "3:1 Safety Factor" but cannot provide the actual breakaway force curve tested on various material thicknesses, they are likely quoting a theoretical maximum, not a tested reality.
2. Misused or distorted CE-style marks: Do not rely on a logo alone. Check whether the CE mark follows the official proportions and whether the supplier can provide the matching technical file and Declaration of Conformity. Treat any "CE-like" mark without documentation as a rejection trigger.
3. No Declaration of Conformity (DoC): A genuine CE-marked magnet under EN 13155 MUST be accompanied by a signed Declaration of Conformity identifying the specific directives and standards it meets. If the supplier refuses to provide a DoC before purchase, disqualify them.
4. Missing Nameplate Data: Both ASME and EN require permanent metal nameplates detailing the manufacturer, serial number, rated capacity, and own weight.

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6. The Procurement & Engineering RFQ Checklist

When authoring a Request for Quotation (RFQ) for a new lifting magnet, copy and paste this checklist into your technical requirements document to legally bind the supplier:

• Standards Compliance: The supplier must explicitly state compliance with ASME B30.20 / BTH-1 (for North America) OR EN 13155 / Machinery Directive (for EU/EEA), and provide the Declaration of Conformity or compliance certificate prior to shipping.
• Proof of Safety Factor: Supplier must provide certified test documentation proving a minimum 3:1 breakaway force over the Safe Working Load (SWL).
• Material-Specific Derating Charts: Supplier must provide derating curves showing the exact lifting capacity on various material thicknesses and air gaps, not just a single "block" rating.
• Power Failure Mitigation: (If purchasing an Electromagnet) Supplier must include a UPS/Battery backup system capable of a 10-minute hold time with optical and acoustic alarms.
• Accidental Release Prevention: The control pendant or remote must utilize a dual-action mechanism to prevent accidental demagnetization.
• Manuals and Maintenance Schedules: Comprehensive documentation in the local language of the end-user facility must be included, detailing daily, weekly, and annual inspection criteria as mandated by the applicable standard.

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7. Beyond Standards: Application Physics Still Apply

Buying a fully compliant EN 13155 or ASME B30.20 magnet does not make you immune to physics. A certified 2,000kg magnet will still drop a 500kg load if you ignore application boundaries.

Standards test magnets on thick, clean, flat steel blocks. If your application involves:

• Thin steel sheets: You will encounter the peeling effect and double-blanking.
• Hot steel: You will exceed temperature limits for permanent magnets.
• Round loads: You must apply specific derating for cylindrical pipes and shafts.

Compliance guarantees the tool is safe; engineering guarantees the application is safe.

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8. Frequently Asked Questions (FAQ)

Q: We are located in South America/Asia. Which standard should we specify?
A: If your country does not have a strict local regulatory equivalent, specifying either ASME B30.20 or EN 13155 is highly recommended as a corporate best practice. Multinational corporations often default to EN 13155 for electrical fail-safes and ASME B30.20 for mechanical load testing to ensure a globally acceptable standard of safety.

Q: Does OSHA recognize EN 13155 in the United States?
A: OSHA relies on the General Duty Clause and primarily references ASME B30.20. While a CE-marked EN 13155 magnet is highly safe, a US inspector will look for ASME compliance documentation, specific ASME warning labels, and ASME-compliant inspection logs. If buying European equipment for a US plant, demand the supplier provides a statement of compliance for ASME B30.20 as well.

Q: Do Electro-Permanent Magnets (EPMs) need the 10-minute battery backup under EN 13155?
A: No. Because EPMs rely on permanent magnetic material to hold the load and only use electricity for a fraction of a second to switch states, a power failure during a lift does not cause the magnetic field to drop. Therefore, they are exempt from the 10-minute backup battery requirement, making them highly desirable for reducing maintenance complexity.

Q: How often does ASME B30.20 require magnets to be inspected?
A: ASME B30.20 dictates three levels of inspection: "Every lift" (visual checks by the operator), "Frequent" (monthly to quarterly, depending on use), and "Periodic" (annual, requiring documented tear-down and detailed structural/electrical analysis).

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Sources & References

To verify compliance in your next procurement cycle, consult the official standard bodies:

1. ASME B30.20-2021: Below-the-Hook Lifting Devices - American Society of Mechanical Engineers.
2. BS EN 13155:2020: Cranes - Safety - Non-fixed load lifting attachments - British Standards Institution.
3. OSHA 29 CFR 1910.179: Overhead and gantry cranes - US Occupational Safety and Health Administration.
4. Machinery Directive 2006/42/EC: EU legislation on machinery safety - European Commission.

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Ready to Specify Compliant Lifting Magnets?

Navigating international safety standards shouldn't slow down your facility's operations. At Lift Magnetics, our engineering team designs and manufactures lifting systems that meet and exceed both ASME B30.20 and EN 13155 requirements.

Whether you need a standalone certified lifter or a fully automated spreader beam system with comprehensive proof-test documentation, we ensure your procurement is risk-free and compliant.

Contact our engineering team today to discuss your application and request a fully documented quotation.