Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
ASME B30.20-2018 — Below-the-Hook Lifting Devices Safety Standard
🧲 ASME B30.20-2018 is the volume of the ASME B30 series dedicated to below-the-hook lifting devices, issued as a revision of ASME B30.20-2013. A below-the-hook lifting device is any load-attachment device suspended beneath the crane hook that directly contacts the load to grasp, support, and release it — including structural and mechanical lifters (spreader beams, bars, frames), vacuum lifters, close-proximity-operated lifting magnets, remotely operated lifting magnets, scrap and material-handling grapples, and clamps. The Standard devotes a chapter to each family, with specific requirements for marking, construction and installation, inspection, testing, maintenance, operation, and instruction manuals — the key reference for selecting, accepting, and safely managing lifting devices in steel mills, shipyards, fabrication shops, and material-handling operations.
💡 Core idea of B30.20: the lifting device is the element of the hoisting chain that touches the load directly and is most exposed to wear and fatigue. The Standard requires every device to be marked with its rated load, to have passed a proof (overload) test, and to receive a visual check before each use. Any device without a nameplate or test record must not be used.
1. Scope and Chapter Framework 📌
B30.20 divides lifting devices into six chapters by grasping principle and operating mode, each with a uniform structure (scope; marking/construction/installation; inspection/testing/maintenance; operation; instruction manuals):
- Chapter 20-1 — Structural and mechanical lifting devices: spreader beams, bars, frames, and articulated loaders that carry the load by structure.
- Chapter 20-2 — Vacuum lifting devices: devices using vacuum pads to lift flat, smooth objects such as plates and glass.
- Chapter 20-3 — Close proximity operated lifting magnets: magnets handling ferrous steel with the operator nearby.
- Chapter 20-4 — Remotely operated lifting magnets: large multi-pad magnets handled from a distance by remote control.
- Chapter 20-5 — Scrap and material-handling grapples: grapples for scrap, waste, and bulk materials.
- Chapter 20-6 — Clamps: clamps that lift steel plate, coils, and sections by gripping force.
⚠️ Below-the-hook devices vary enormously in construction. Before selection, confirm the device family (structural/vacuum/magnet/grapple/clamp) and then apply that chapter’s inspection and testing requirements — generic “universal device” management risks missing chapter-specific clauses.
2. Category-Specific Technical Requirements 🔧
| Chapter | Device Family | Typical Forms | Key Safety Requirement |
|---|---|---|---|
| 20-1 | Structural/mechanical lifters | Spreader beams, bars, frames | Stress analysis, permanent rated-load marking, periodic NDT |
| 20-2 | Vacuum lifters | Vacuum pad groups, pump systems | Vacuum retention and alarm, fail-safe, pad area sized to load |
| 20-3 | Close-proximity magnets | Body-mounted lifting magnets | Control circuit, power-loss hold, operator stand-off distance |
| 20-4 | Remotely operated magnets | Large multi-pad remote magnets | Remote interlocks, power-loss hold, load monitoring |
| 20-5 | Scrap grapples | Grapples (hinged jaws) | Jaw/pin wear checks, closed-position locking, no accidental opening |
| 20-6 | Clamps | Plate, coil, and section clamps | Grip force and anti-release, jaw wear, self-locking mechanism |
All device families must satisfy common baseline requirements: marking (manufacturer, rated load, date, and load direction/service where applicable); construction (materials, welds, and heat treatment per calculation and standard, with fatigue-loaded parts designed to applicable codes); proof-load testing (new or overhauled devices tested to a multiple of rated load, with a documented record); and instruction manuals (operation, inspection, maintenance, and replacement criteria).
🚨 Vacuum and magnetic lifters are “power-dependent” devices: if power, vacuum, or current is lost, the load can drop instantly. The Standard requires fail-safe and alarm devices, and prohibits standing under the load. Confirm the contact surfaces are clean, free of oil, and the load is not tilted or off-center before lifting.
3. Inspection, Testing, and Maintenance 📋
B30.20 prescribes a systematic inspection regime for every device family: initial inspection (at acceptance/first use) verifying the nameplate, test record, and structural integrity; frequent inspection (each shift or daily) by operators/users for visible wear, deformation, cracks, looseness, and hydraulic/vacuum/electrical condition; and periodic inspection (monthly/quarterly/annual) by qualified personnel, using nondestructive testing (magnetic particle, ultrasonic, dye penetrant) on welds and stress-concentrating areas where appropriate.
For testing: new or overhauled devices must pass a proof-load test (typically a multiple of rated load) with records retained; magnetic and vacuum devices also receive functional tests to verify pick-up, release, and fail-safe operation. Maintenance follows the manufacturer’s manual, wearing parts (jaw faces, pads, grapple pins, cables, and hoses) are replaced when criteria are met, and all maintenance and inspection records are kept.
| Inspection Type | Interval | Inspection Points |
|---|---|---|
| Initial inspection | Acceptance / first use | Nameplate, test record, structural integrity, functional test |
| Frequent inspection | Every shift / daily | Visible cracks, deformation, wear, looseness, electrical/vacuum/hydraulic state |
| Periodic inspection | Monthly/quarterly/annual | Detailed check plus NDT, fatigue zones, replacement determination |
| Proof-load test | After new install/overhaul | Test to a multiple of rated load, issue record, update tag |
💡 The “mouths” of clamps and grapples (jaw faces and shells) wear most and directly govern grip safety: mark a minimum-thickness line on each clamp and retire it at the line; measure grapple pin and bushing clearance periodically and replace when excessive to prevent opening in mid-air.
4. Engineering Practice Essentials 🛠️
- 🔍 Selection workflow: define load weight, dimensions, and shape (plate/coil/section/bulk) → choose the matching device family and size with rated load at least ~1.25× the job load → verify hook interface dimensions and swing clearance with the crane.
- 🔧 Ledger and unique ID: give every device a record (ID, manufacturer, rated load, test date, inspection log) and permanently mark the ID on the device — “one device, one file.”
- 📊 Off-center and combined use: with multi-point spreaders, distribute the load per actual point forces and never exceed a single point’s rating; recheck vacuum/magnet capacity against contact area and material.
- 📋 Retirement: devices meeting the Standard’s or manufacturer’s replacement criteria (cracks, permanent deformation, excessive wear, functional failure) are immediately withdrawn and scrapped — never downgraded for other service.
5. Frequently Asked Questions ❓
❓ Q: How do B30.20 and slings (B30.9) relate?
A: B30.9 covers flexible slings (wire-rope, chain, and synthetic-web slings); B30.20 covers rigid load-attachment devices (beams, grapples, clamps, magnetic/vacuum lifters). If a lift uses both slings and a beam or lifting lugs, apply the relevant requirements of each volume.
A: B30.9 covers flexible slings (wire-rope, chain, and synthetic-web slings); B30.20 covers rigid load-attachment devices (beams, grapples, clamps, magnetic/vacuum lifters). If a lift uses both slings and a beam or lifting lugs, apply the relevant requirements of each volume.
❓ Q: Is an overload test mandatory for lifting devices?
A: Yes. New or overhauled devices must undergo a proof-load test to a multiple of rated load (typically around 125%) to verify structural strength, with a retained record — this is the prerequisite for a device to be “qualified.”
A: Yes. New or overhauled devices must undergo a proof-load test to a multiple of rated load (typically around 125%) to verify structural strength, with a retained record — this is the prerequisite for a device to be “qualified.”
❓ Q: Will a magnetic lifter drop the load immediately on power failure?
A: Proper designs provide power-loss retention (e.g., battery backup/dual supply) and alarms, but retention time is finite. Hence the Standard strictly forbids standing under the load, keeps travel paths clear of people, and requires periodic verification of the fail-safe function.
A: Proper designs provide power-loss retention (e.g., battery backup/dual supply) and alarms, but retention time is finite. Hence the Standard strictly forbids standing under the load, keeps travel paths clear of people, and requires periodic verification of the fail-safe function.
🔍 Q: Can inspection intervals for clamps and grapples be relaxed?
A: No. Wear and fatigue accumulate, and the Standard’s and manufacturer’s intervals and replacement criteria are minimums. Devices in high-frequency, impact, or high-temperature service should be inspected more often with NDT added.
A: No. Wear and fatigue accumulate, and the Standard’s and manufacturer’s intervals and replacement criteria are minimums. Devices in high-frequency, impact, or high-temperature service should be inspected more often with NDT added.
