Safety Compliance and Fail-Safe Mechanisms in Magnetic EOAT: ISO 10218-2 and PL Buyer's Guide

When specifying robotic End-of-Arm Tooling (EOAT) for heavy ferromagnetic payloads, the #1 priority for engineering and procurement teams is safety. Dropping a 50kg steel blank or a sharply edged stamped component due to a sudden power outage is a catastrophic risk that modern manufacturing cells must engineer out.

In the realm of magnetic gripping, the distinction between standard electromagnets and Electro-Permanent Magnets (EPMs) is the foundation of robotic safety compliance. With ISO 10218-2:2025 now published for industrial robot applications and robot cells, and ISO 13849-1:2023 current for safety-related parts of control systems, understanding how to source, specify, and integrate fail-safe magnetic EOAT is critical.

This comprehensive guide breaks down the application boundaries, procurement checklists, and compliance frameworks for fail-safe magnetic grippers. We will explore how EPMs interact with ISO standards, where their limits lie, and how to structure your RFQ to ensure your integrator delivers a system that is both compliant and highly productive.

Scope, Date, and Limits

This guide was reviewed on July 21, 2026 for global industrial buyers, robot integrators, and manufacturing engineers specifying magnetic grippers for ferromagnetic workpieces. It applies to electro-permanent magnetic EOAT in robot cells where power-loss retention, part-present sensing, shear-force margin, and risk-assessment evidence are part of supplier selection.

It does not replace a certified machine risk assessment, a local legal compliance review, or the purchased text of ISO standards. Treat it as a buyer-side specification framework: verify the final robot cell against the locally adopted edition of ISO 10218-2, ISO 13849-1, and any applicable regional or industry-specific rules.

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1. The Core Hazard: The "Power-Loss Drop"

The most immediate danger in robotic material handling is the unintended release of a workpiece. In traditional vacuum gripping or standard electromagnetic gripping, a continuous supply of energy (compressed air or electrical current) is required to maintain the holding force.

If a factory experiences a sudden blackout, or if a cable on the robot arm is severed, standard electromagnets instantly lose their magnetic field. The payload drops immediately.

The Electro-Permanent Magnet (EPM) Solution

An Electro-Permanent Magnet (EPM) operates on a fundamentally different physical principle. It uses an electrical pulse—typically lasting less than a second—only to switch the polarity of internal magnets.

1. Magnetization (ON): A short current pulse aligns the internal permanent magnets (often Alnico and Neodymium) so their magnetic flux is driven outward into the workpiece.
2. Holding: Once magnetized, zero electrical power is required. The permanent magnets maintain a continuous, unyielding grip on the steel part.
3. Demagnetization (OFF): A reverse current pulse realigns the internal magnets so the flux is short-circuited internally, releasing the part.

Because EPMs rely on permanent magnets for the actual holding phase, they are intrinsically safe against power loss. If power is cut mid-cycle, the magnetic flux remains exactly as it was. The workpiece stays securely attached to the robot.

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2. Navigating ISO Standards for Magnetic EOAT

Procurement and engineering teams cannot simply buy an EPM gripper and declare their robot cell "safe." Industrial automation safety is holistic, governed by a series of interconnected ISO standards.

ISO 10218-1 and ISO 10218-2 (Robots and Robotic Devices)

These are the foundational standards for industrial robot safety. For new global projects, specify the current locally adopted edition; ISO lists ISO 10218-2:2025 as the published replacement for the withdrawn 2011 edition.

• ISO 10218-1 focuses on the robot manufacturer (the manipulator and controller).
• ISO 10218-2 focuses on the robot application and cell integration, including the end-effector (EOAT), workpiece, commissioning, operation, maintenance, and decommissioning assumptions.

Buyer-side safety expectation: the robot cell design must account for hazardous workpiece release during power loss, control failure, emergency stop, collision, commissioning, maintenance, and recovery scenarios. Confirm the exact requirement language in the purchased standard and in your regional adoption of ISO 10218-2.

By selecting an EPM gripper, procurement reduces a significant portion of the power-loss drop risk. However, integrators must still address how the robot behaves when an E-Stop is pressed (e.g., does the arm brake aggressively enough to cause the part to slide off via inertia?).

ISO 13849-1 (Safety-Related Parts of Control Systems - SRP/CS)

This standard defines how control systems should be designed to achieve a specific Performance Level (PL), ranging from PL a (lowest) to PL e (highest reliability).

When integrating a magnetic gripper, the safety logic must ensure the robot does not move unless the part is securely gripped.

• PL Requirement: If a risk assessment determines a high risk of injury (e.g., PL d required), the controller must reliably know the gripper's state.
• Sensing: Modern EPM grippers for robotic applications must include integrated sensors (e.g., inductive proximity sensors or magnetic flux sensors) to provide feedback to the PLC.
• Dual-Channel: For higher PL ratings, the signals confirming "Magnet ON" and "Part Present" may need to be dual-channel to prevent a single point of failure in the wiring from falsely signaling a safe state.

ISO/TS 15066 and Cobot Applications

ISO/TS 15066 remains a key reference for collaborative robot applications and is complementary to ISO 10218-2:2025. When using magnetic grippers on cobots, the primary concern shifts from just dropping the part to the hazards introduced by the part itself (sharp edges, mass) during a collaborative collision. Even if the gripper is fail-safe, the payload might mandate fencing or safety scanners.

For collaborative cells, use this article together with the cobot gripper selection guide so payload, flange, cable routing, and operator-interaction assumptions are reviewed before the EOAT is released for quotation.

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3. Visualizing the EPM Safety Interlock

To achieve compliance, the EPM gripper must communicate bi-directionally with the robot controller. The safety case is not just "magnet ON"; it is a verified chain from robot command to controller pulse, gripper state, workpiece contact, and motion permission.

The PLC should only authorize the robot to accelerate if it receives the required safe-state feedback from the EPM controller and sensors, confirming both that the magnetization pulse was successfully delivered and that the part is physically detected against the gripper face.

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4. Understanding Application Boundaries and Non-Power Risks

Procurement teams must understand that fail-safe against power loss does not mean infinite holding force. EPM grippers have strict application boundaries. If these boundaries are crossed, a catastrophic drop can still occur.

The Impact of Air Gaps and Coatings

Magnetic force decreases exponentially as the distance between the magnet face and the steel workpiece increases. This distance is known as the "air gap." Air gaps aren't always just empty space; they include:

• Paint, rust, or scale on the metal.
• Dirt, grease, or metallic chips accumulating on the gripper.
• Uneven or warped workpiece surfaces.

If a risk assessment assumes a clean, flat steel plate, but the actual process involves heavily scaled forgings, the gripping force may drop by 50% or more, invalidating the safety margins.

For the force calculation workflow behind these assumptions, see the magnetic gripper sizing guide for air gaps and coatings.

Dynamic Forces: Shear vs. Breakaway

• Breakaway Force: The force required to pull the part straight down, perpendicular to the magnet face.
• Shear Force: The force required to slide the part sideways across the magnet face. Magnetic shear force is typically only 20% to 30% of the breakaway force.

During a high-speed robot emergency stop (E-Stop), the robot arm decelerates violently. If the EOAT is oriented vertically, inertia will apply massive shear forces to the workpiece. If the shear force exceeds the friction and magnetic attraction, the part will slide off and become a dangerous projectile.

Mitigation Strategy Table

To maintain safety compliance, engineering must design mitigations for these non-power-loss risks.

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5. Procurement Checklist for Safety-Rated Magnetic Grippers

When issuing an RFQ (Request for Quotation) for a magnetic EOAT system, procurement and engineering must align to ensure the quoted hardware is capable of meeting safety standards. Do not just ask for "a magnet that lifts 50kg."

Use this checklist to evaluate supplier proposals:

• EPM Technology Verification: Confirm the technology is Electro-Permanent, NOT standard Electromagnetic. It must not require a UPS (Uninterruptible Power Supply) to maintain grip.
• Integrated Sensing Suite: Does the gripper include built-in inductive proximity sensors or flux sensors? (Required for PLC interlocks).
• Shear Force Data: Does the supplier provide documented shear force ratings, or only breakaway (pull) force? (Shear data is critical for robot acceleration planning).
• Air Gap Curves: Has the supplier provided force/air-gap curves to prove the magnet will safely hold your specific material condition (e.g., rusted or painted)?
• Controller Communication: Does the EPM controller support industrial safety protocols (e.g., PROFIsafe, CIP Safety, or dual-channel discrete I/O) to achieve the required Performance Level (PL)?
• Friction Enhancements: For high-speed applications, are friction rings or high-coefficient coatings applied to the magnet poles to resist sliding?
• Material Thickness Limits: Has the supplier confirmed the magnetic saturation depth? (If your steel is too thin, magnetic flux passes through and is wasted, reducing holding force).

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6. Real-World Applications and the Bottom Line

The transition from vacuum or pneumatic gripping to Electro-Permanent Magnetic gripping is often driven by energy savings and maintenance reduction. However, the intrinsic safety of EPMs makes them the gold standard for handling heavy steel components like automotive frames, forging blanks, and structural steel beams.

If your team is still comparing gripping technologies, review magnetic gripper vs vacuum gripper for sheet metal before locking the EOAT concept.

By understanding that safety extends beyond "what happens when the lights go out," procurement teams can ask the right questions about shear forces, sensing, and control integration. A properly specified EPM gripper, integrated with respect to ISO 10218-2 and ISO 13849-1, provides unparalleled peace of mind on the factory floor.

7. Procurement and Engineering Decision Table

When specifying a fail-safe magnetic gripper, buyers must communicate specific parameters to suppliers to avoid compliance and performance failures. This decision table outlines the critical dimensions, boundaries, and communication fields required.

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8. Frequently Asked Questions (FAQ)

Does an EPM gripper negatively impact our robotic cycle times compared to pneumatics?
A typical MAG or DEMAG pulse takes between 0.3 to 1.0 seconds. While vacuum cups might engage slightly faster, the elimination of mechanical clamping time often results in a net-zero impact. Buyers should ask suppliers for exact pulse durations for their specific EOAT size.

How do we verify the actual holding force on our specific, oily workpieces before integration?
You should mandate a factory acceptance test (FAT) or send sample workpieces to the EPM manufacturer. They can use load cells to generate an empirical force/air-gap curve specific to your part's alloy, surface roughness, and oil film.

Can we run an EPM gripper directly off the robot's 24V wrist supply?
Generally, no. EPMs require high-current pulses (often 400V or high-amperage 24V/48V via dedicated capacitors) to switch the magnetic polarity. You typically need to route a dedicated power cable down the robot arm from a separate EPM controller cabinet.

Is a secondary mechanical catch always required for overhead EPM lifting?
Not always, but it heavily depends on your specific risk assessment. If a part drop could injure personnel and the application involves high dynamic shear risks, a secondary catch might be required. However, for fully fenced, automated cells without human access beneath the payload, the EPM's fail-safe holding is usually sufficient.

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References / Sources

1. ISO 10218-2:2025 - Robotics — Safety requirements — Part 2: Industrial robot applications and robot cells. Current ISO page for robot application and cell integration safety. View on ISO.org
2. ISO 13849-1:2023 - Safety of machinery — Safety-related parts of control systems — Part 1: General principles for design. Current ISO page for Performance Level (PL) design principles. View on ISO.org
3. ISO 10218-2:2011 - Withdrawn previous edition of Robots and robotic devices — Safety requirements for industrial robots — Part 2: Robot systems and integration. Use only as historical context when reviewing older specifications. View on ISO.org

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Ready to specify a fail-safe magnetic gripping solution for your robotic cell? Our engineering team supports ISO-aligned EOAT specification, providing full air-gap analysis, shear force calculations, and integration support. Contact our engineering team today with your robot model, workpiece drawings, surface condition, cycle target, and required PL so we can review the magnetic EOAT assumptions before quotation.