TECHNICAL ARTICLES
Eyebolt WLL and Angular Loading: Why the number on the tag isn’t the number you can lift
The figure stamped on a collared eyebolt made to AS 2317.1:2018 is its transverse WLL – the side-pull rating, and the lowest one the standard permits. It is marked in tonnes, without the letters "WLL", with arrows showing the direction of pull. The higher axial and paired-configuration ratings aren't on the eyebolt at all – they come from Table 4.3 of the standard. Plan a lift off the wrong number and the eyebolt can be stamped, in date and apparently within its rating – and still deform.
This article explains what the marking means, how AS 2317.1:2018 actually rates axial, transverse and angled lifts, and when the job needs a swivel hoist ring instead of a standard eyebolt.
Key terms
Plain vs collared: the collar changes the load path
On a plain eyebolt, the entire load runs through the thread engagement. Any angle introduces a bending moment at the thread root – a geometry the thread was never designed for. Plain eyebolts are vertical-only. If the sling isn't running straight up the shank, it's the wrong component.
On a collared eyebolt, the shoulder seats against the parent material and carries the side load by bearing, instead of resolving it through thread bending. That's what allows angular loading – within the limits set out below.
Both require full thread engagement – at least the nominal thread diameter, increasing to 1.75 × the diameter in cast iron and 3 × in aluminium (clause 4.4.5). A collared eyebolt with inadequate thread depth is effectively unrated regardless of collar geometry.
On-site rule of thumb: if it doesn't have a visible collar or shoulder at the base, treat it as a plain eyebolt – vertical loading only.
Fitting it right
Why eyebolts fail at loads within the axial WLL
At an angle, the sling tension splits into two components: one in line with the shank (axial), and one across it (lateral). The axial WLL covers the first only. The lateral component drives a bending moment across the eye-to-shank transition – and as the angle opens, that moment climbs, to the point of yield or fracture, even while the total load sits under the axial figure quoted in a catalogue or lift plan.
The tell is a bent or twisted shank with the eye pulled toward the line of load. That's a textbook angular-loading failure. If you've seen it on a returned piece of plant, that's what caused it.
How AS 2317.1:2018 actually rates loading
What's stamped on the eyebolt
Under AS 2317.1:2018, a collared eyebolt is marked with its transverse WLL in tonnes – a bare number, without the letters "WLL" – with arrows showing the side-pull direction (clause 2.5.3(d)). A compliant M24 is stamped 0.62 with arrows. Its axial WLL is 2.5 t – four times the stamp.
Older and imported eyebolts: eyebolts made to the superseded AS 2317–1998, and imported eyebolts made to other standards, may carry no WLL marking, or one on a different basis. Check the marking and the certificate before working from any stamped figure.
AS 2317.1:2018 – Lifting points, Part 1: Collared eyebolts and collared eyenuts – Grade 4 – separates three loading conditions worth keeping distinct:
1. Single eyebolt, axial
Full axial WLL – four times the stamped transverse figure. This is the baseline every other figure is derived from.
2. Transverse (trunnion) loading
A collared eyebolt can be side-loaded in the plane of the eye, but at a heavily reduced WLL. A single eyebolt loaded transversely is rated at 0.25 × axial WLL, the figure stamped on it. A pair loaded transversely under a lifting beam is rated at 0.5 × axial WLL. This is a rated condition, not a free pass.
3. Lateral loading (out of the plane of the eye)
Not permitted. The standard allows only a 5° tolerance off the plane of the eye. Beyond that, the load is outside the rating entirely.
For a two-leg sling on a pair of eyebolts, the standard rates the configuration by included angle, applied against the single-eyebolt axial WLL.
Table A – Two-leg sling on a pair of collared eyebolts (AS 2317.1:2018)
| Included angle (between legs) | ≈ Per-leg angle from vertical | Factor × single-eyebolt axial WLL | Example: M24 (2.5 t axial) |
|---|---|---|---|
| 30° | ~15° | 1.25 | 3.1 t assembly |
| 60° | ~30° | 0.80 | 2.0 t assembly |
| 90° | ~45° | 0.50 | 1.25 t assembly |
| Over 90° | Over ~45° | Outside the table. The standard says not to exceed 90°. | |
The factor gives the WLL of the paired configuration as a whole, referenced to one eyebolt's axial WLL. The standard tabulates nothing beyond 90° included – if the geometry pushes the legs wider than 90° between them, you're outside the table and need a different solution.
More than two eyebolts: without a load-sharing device, only two eyebolts can be counted as carrying the load.
Continuous slings: never run a continuous sling through a pair of eyebolts (clause 4.7). Use a sling with individual legs, one leg to each eyebolt.
Table B – Grade 4 collared eyebolt axial WLL by size (AS 2317.1:2018)
| Size | Axial WLL (t) | Size | Axial WLL (t) |
|---|---|---|---|
| M10 | 0.25 | M36 | 6.3 |
| M12 | 0.40 | M39 | 7.0 |
| M16 | 0.80 | M42 | 8.0 |
| M20 | 1.6 | M48 | 10.0 |
| M22 | 2.0 | M56 | 15.0 |
| M24 | 2.5 | M64 | 20.0 |
| M30 | 4.0 | M72 | 25.0 |
| M33 | 5.0 | M76 | 30.0 |
These are axial ratings. The figure stamped on each eyebolt is its transverse WLL – 0.25 × the axial value shown. M10 is listed for completeness. The standard advises against anything under M12 for general lifting.
A note on manufacturer data sheets: many product data sheets – and most US-origin sources – present per-eyebolt derating measured from vertical, which is a different framing to the AS 2317.1 included-angle table above. Both are legitimate; they are not interchangeable. Use the manufacturer's own rated figures for their specific product, use AS 2317.1's table for the standard's paired configuration, and never mix a factor from one framing into the other. Ignore ASME B18.15 / B30.26 derating figures – those are US standards and don't apply here. Before using any figure, check which rating the marking on the eyebolt actually shows – on an eyebolt made to AS 2317.1:2018 it is the transverse WLL, not the axial.
Worked example: two-point lift with angled slings
A 3,000 kg load lifted on two M24 collared eyebolts with a two-leg sling, legs at roughly 30° from vertical – an included angle of about 60°. Each eyebolt is stamped 0.62 t (transverse); axial WLL is 2.5 t. Can it proceed?
Step 1 – Configuration WLL at 60° included
Step 2 – Compare to the load
Options:
Grade 4 M24 is rated 2.5 t axial – if a data sheet or an older lift plan shows 3.2 t for this size and grade, that figure doesn't exist in AS 2317.1:2018. Check which rating any quoted or marked figure represents before you use it – the stamp on a 2018-compliant M24 reads 0.62, its transverse WLL. This is exactly the scenario our technical team assists with on engineered lift plans – contact us if you're working through a lift like this.
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Controlling the angle on site
The included angle depends on eyebolt spacing and hook height. The further apart the points and the higher the hook, the closer to vertical the legs run. On complex lifts, calculate and confirm the angle in the lift plan before the lift – don't eyeball it on the day. For repeat lifts on the same plant, some sites mark a minimum compliant hook height on the lift study, so the dogman can confirm before the hook takes load. Where the geometry can't give a compliant angle, that's the swivel-hoist-ring case.
When to use a swivel hoist ring instead
A swivel hoist ring's shank bolts into the load; the ring rotates 360° and pivots (typically 0–90° from vertical, manufacturer-dependent). Because it self-aligns to the line of pull, the shank stays essentially axial regardless of sling angle, and the manufacturer's WLL applies across the range – no included-angle reduction.
Specify a swivel hoist ring when:
Swivel hoist rings cost more per unit, but they remove an entire class of calculation error and take the angular-loading failure mode off the risk register. On complex plant lifts, that's usually the right trade-off.
Eyebolt inspection under AS 2317.1:2018
Eyebolts are checked at three points. The before-use check is a visual one; periodic inspections must be carried out by a competent person.
Table C – Guide to periodic inspection intervals (AS 2317.1:2018, Table 4.2)
| Lifts per week | Periodic inspection interval |
|---|---|
| 1–5 | 12-monthly |
| 6–25 | 6-monthly |
| 26–200 | 3-monthly |
| 201 or more | Monthly |
A guide only: the end user sets the inspection schedule according to the duty cycle (M3 under AS 1418.1) and the environment the eyebolt works in.
Remove from service on any of the following:
If an eyebolt shows shank bending or eye distortion, don't just bin it – check whether the plant it came off has been re-fitted with the same rigging arrangement. The failure is telling you the loading condition is wrong. Fix one eyebolt without fixing the geometry and the next one fails the same way.
Standards current as at October 2026. AS 2317.1:2018 Lifting points, Part 1: Collared eyebolts and collared eyenuts – Grade 4; no Part 2 published at the time of writing.
Ranger Lifting Rigging Safety has inspected, tested, certified and supplied lifting and rigging equipment across NSW, QLD, VIC and SWQ since 1998. Our inspectors are trained and credentialed specifically for equipment examination, working to the relevant Australian Standards within a NATA-accredited framework.
If you need any technical information, please get in touch — we’d be happy to assist.