Can a plain eyebolt be loaded sideways?

No. Per BS 4278:1984, a plain (non-collared) eyebolt is rated only for axial loads. Any angle off-axis is prohibited. For side loads use a collared (shoulder) eyebolt or a welded pad eye.

What derating applies to collared eyebolts at 45°?

Per BS 4278 and LEEA COPSURE 1.5, a collared eyebolt at 45° from axis derates to ~30% of its axial WLL. At 90° lateral pull the derating is ~25%. The collar must be fully seated against the parent metal.

What thread engagement is needed?

Per BS 4278 the eyebolt must be threaded fully home, with the collar (if collared) bedded against the parent material with no shim or paint between. Minimum engagement is typically 1.5 × thread diameter for steel, 2 × for aluminium.

What's the difference between D and bow shackles?

D (chain) shackles have a parallel-sided body — best for in-line axial loads. Bow (anchor) shackles have a wider rounded bow — accept multi-leg attachments and tolerate up to 45° side load better than D-shackles.

Grade M, S, or T — which to use?

Mild-steel (M, grade 4): general industrial, lower SWL. Special-strength (S, grade 6): typical alloy. T (grade 8): highest WLL per body size, alloy steel — used where weight or geometry matters. The tool maps each to EN 13889:2003+A1:2008 table values.

When does side-loading require derating?

Any pin-loading off-axis derates the shackle. For D-shackles, derating starts at 45° and reaches ~50% at 90°. Bow shackles tolerate side load better — typically full SWL up to 45°, then derate to 70% at 90°.

F = ΔP × A — the lift force is vacuum level times total pad area. m_allowable = (F × η_surface) / (g × SF). η is the surface efficiency (1.0 smooth, 0.7 rough, 0.35 porous, 0.25 oily); SF is the LEEA safety factor (2 minimum, 4 for personnel exposure).

Why such a high safety factor over personnel?

EN 13155:2020 requires SF ≥ 4 for vacuum lifters used over people. The vacuum can fail instantly (power loss, seal damage). Redundant pumps and reserve tanks are also typically required for public-place lifts.

Are porous materials liftable?

Marginally — concrete and rough wood derate to ~35% efficiency and need higher pump capacity to maintain vacuum. Avoid for routine lifts; use mechanical clamps instead.

Why does plate thickness matter?

Magnetic lifters are rated on an 'infinitely thick' plate that absorbs the full magnetic field. Thinner plates saturate, reducing the holding force. Below ~30% of the rated reference thickness, derating becomes severe.

What materials cannot be lifted?

Stainless steel (austenitic grades 304/316), aluminium, copper, brass, plastics — all non-ferrous or non-magnetic and cannot be lifted at all. The tool returns zero capacity for these.

Does mill scale or paint affect capacity?

Yes — any air gap > 0.1 mm reduces field penetration. Mill scale, primer paint or heavy rust can drop capacity to 30–55% of rated. Clean the contact zone where possible.

Can vertical clamps be used horizontally?

No. Vertical plate clamps grip on a downward bite and will release immediately if the load goes horizontal. Use a horizontal-rated clamp instead — these are mechanically different.

Why must the plate be free of paint and rust at the grip zone?

Plate clamps work through a cam-and-tooth bite into the parent metal. Paint and heavy mill scale lubricate the grip and cause slippage. Clean a 50 mm band at the lift point to bare metal.

How are paired clamps loaded?

The calculator shows nominal share — 50% per clamp for paired lifts. LEEA additionally recommends each clamp be rated for the full load as a redundancy check, so a slip on one still holds the plate. Verify both conditions when planning a paired lift.

What's the side-pull envelope?

Most beam clamps allow up to 6° from vertical at full WLL. Beyond 6°, capacity drops 5% per degree (floored at 40%) and the effective pull becomes F/cos α. Above ~30° most manufacturers prohibit use.

What's the difference between parallel-flange and taper-flange beams?

Parallel-flange (UB, W-section) have constant flange thickness — accept most plain trolleys. Taper-flange (RSJ, classic I-beam) flanges thin towards the edge — require a clamp specifically rated for taper, or shims under standard clamps.

Do beam clamps need a competent person's check?

Per LOLER 1998 reg. 9 and LEEA COPSURE 13, beam clamps are lifting accessories and require 6-monthly thorough examination by a competent person, plus a pre-use inspection by the operator.

Lifting Hardware SWL – Shackle, Eyebolt, Clamp

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33Eyebolt / Eyenut SWL Derating

Per BS 4278:1984 / LEEA COPSURE 1.5, an eyebolt loaded off-axis loses capacity rapidly. Standard (non-collared) eyebolts must be loaded along the bolt axis. Collared (shoulder) eyebolts can take limited side load. Lateral pull (90°) on a non-collared eyebolt is prohibited.

Eyebolt type

Standard (no collar) Collared / shouldered Dynamic (rotating ring)

Thread size

Load angle from bolt axis (°) i

0°0°90°

Derated SWL

— kg per eyebolt

—

Axial SWL (0°)—

Angle factor—

ReferenceBS 4278:1984 · LEEA COPSURE 1.5

—

34Shackle SWL Lookup

SWL lookup for D (chain) and bow (anchor) shackles per EN 13889:2003+A1:2008 and US Federal Specification RR-C-271. Side-loading reduces SWL — bow shackles tolerate side-load better than D-shackles. Reference LEEA COPSURE 6.4.

Shackle body shape

D / chain Bow / anchor

Body diameter (mm)

Grade

Side-load angle (°) i

0°0°90°

Working Load Limit

— tonnes effective SWL

—

Rated SWL (in-line)—

Side-load factor—

Pin diameter—

ReferenceEN 13889:2003+A1:2008 · LEEA COPSURE 6.4

—

35Vacuum Lifter Capacity

Theoretical lift force of a vacuum lifter: F = ΔP × A_total. Apply the LEEA-recommended safety factor (≥ 2 for routine lifts, ≥ 4 where personnel could be exposed). Per LEEA COPSURE 8 and EN 13155:2020.

Vacuum level achieved (kPa below atmosphere)

2060 kPa90

A 60 kPa vacuum at sea level gives ΔP ≈ 60 kPa = 6.12 N/cm².

Number of pads

Area per pad (cm²) Round pad: A = π·r². 170 mm dia ≈ 227 cm².

Surface type

Safety factor (LEEA)

Lift capacity

— kg allowable load

—

Theoretical lift force—

Total contact area—

Surface efficiency—

Applied SF—

ReferenceLEEA COPSURE 8 · EN 13155:2020

—

36Magnetic Lifter Derating

Permanent / electro-permanent magnetic lifter capacity is rated on a thick, flat, low-carbon plate with a clean, smooth surface. Real plates derate the rated SWL. Per LEEA COPSURE 9 and EN 13155:2020.

Magnet rated SWL (kg, on reference plate)

Plate thickness (mm) Rated capacity assumes thickness ≥ manufacturer's reference (often 50 mm). Below this, force drops sharply.

Reference thickness (mm)

Material

Surface roughness / air gap

Plate shape

Safety factor

Working capacity

— kg effective SWL

—

Thickness factor—

Material factor—

Surface factor—

Shape factor—

Combined derate—

ReferenceLEEA COPSURE 9 · EN 13155:2020

—

37Plate Clamp Working Load

Selection check for vertical plate clamps per LEEA COPSURE 16. The plate must fall within the clamp's jaw range, and the load must be within the clamp's WLL. Most clamps require the plate to be free of rust and paint at the gripping zone.

Clamp WLL (kg)

Clamp jaw range — minimum thickness (mm)

Clamp jaw range — maximum thickness (mm)

Plate thickness (mm)

Plate weight (kg)

Lifting orientation

Surface condition at gripping point

Number of clamps in lift

Selection

—

Per-clamp load—

Clamp utilisation—

Thickness range check—

Surface check—

ReferenceLEEA COPSURE 16

—

38Beam Clamp / Trolley Flange Check

Verifies beam-flange compatibility and side-load envelope per LEEA COPSURE 13 and EN 13155:2020. The flange must fall inside the clamp's published flange-thickness AND flange-width range, and any side pull (non-vertical) must fall inside the manufacturer's allowable angle (typically ≤ 6°).

Clamp / trolley type

Beam clamp Trolley Girder clamp

Clamp WLL (kg)

Clamp flange-thickness range (mm) — min / max

Clamp flange-width range (mm) — min / max

Beam flange thickness (mm)

Beam flange width (mm)

Load (kg)

Side-pull angle from vertical (°)

0°0°20°

Beam flange angle (taper)

Selection

—

WLL utilisation—

Flange thickness check—

Flange width check—

Side-pull check—

Effective load (with angle)—

ReferenceLEEA COPSURE 13 · EN 13155:2020

—

For training purposes only. All hardware selection must follow the manufacturer's published WLL and the relevant standard. Quoted derating factors are typical industry values — your equipment's data plate is authoritative.

48PPE Rotation Tracker

Tracks PPE issue, use intensity and discard intervals. Auto-flags items past their service life per EN 397 (hard hats 5 y), EN 388 (gloves), EN 374 (chem gloves) and EN 361 (harnesses 10 y / 5 y typical).

PPE type

Issue date

Use intensity

Inspection status (last visual check)

Result

— days to discard

—

Discard date—

Standard service life—

Adjusted for use—

Recommendation—

Reference: EN 397, EN 361, EN 388, EN 374, EN 149, EN 166, EN ISO 20345. Manufacturer manual overrides where stricter.

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LEEA Hardware SWL Tools

33Eyebolt / Eyenut SWL Derating

Derated SWL

34Shackle SWL Lookup

Working Load Limit

35Vacuum Lifter Capacity

Lift capacity

36Magnetic Lifter Derating

Working capacity

37Plate Clamp Working Load

Selection

38Beam Clamp / Trolley Flange Check

Selection

48PPE Rotation Tracker

Result

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