Home  /  LEEA Hardware SWL

LEEA Hardware SWL Tools

Working-Load-Limit and selection tools for the most-used lifting accessories — eyebolts, shackles, vacuum and magnetic lifters, plate clamps and beam clamps. Each calculator follows the relevant LEEA COPSURE chapter and EN / ASME standard.

33Eyebolt / Eyenut SWL Derating

Per BS 4278 / 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.

0°0°90°

Derated SWL

— kg per eyebolt
—
Axial SWL (0°)—
Angle factor—
ReferenceBS 4278 · LEEA COPSURE 1.5

—

34Shackle SWL Lookup

SWL lookup for D (chain) and bow (anchor) shackles per EN 13889:2003 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.

0°0°90°

Working Load Limit

— tonnes effective SWL
—
Rated SWL (in-line)—
Side-load factor—
Pin diameter—
ReferenceEN 13889 · 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.

2060 kPa90
A 60 kPa vacuum at sea level gives ΔP ≈ 60 kPa = 6.12 N/cm².
Round pad: A = π·r². 170 mm dia ≈ 227 cm².

Lift capacity

— kg allowable load
—
Theoretical lift force—
Total contact area—
Surface efficiency—
Applied SF—
ReferenceLEEA COPSURE 8 · EN 13155

—

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.

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

Working capacity

— kg effective SWL
—
Thickness factor—
Material factor—
Surface factor—
Shape factor—
Combined derate—
ReferenceLEEA COPSURE 9 · EN 13155

—

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.

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. 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°).

0°0°20°

Selection

—
—
WLL utilisation—
Flange thickness check—
Flange width check—
Side-pull check—
Effective load (with angle)—
ReferenceLEEA COPSURE 13 · EN 13155

—

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.