Collared Eye Bolt
Uncollared Eye Bolt
Anatomy of an Eye Bolt
Eye (Ring)
The closed loop at the top of the bolt through which a shackle or sling is attached. Must be free of cracks, distortion, or wear.
Shank (Threaded)
The threaded body that screws into the tapped hole in the load. Thread must be fully engaged — no visible threads above the surface.
Collar (Shoulder)
A forged shoulder at the base of the eye on collared eyebolts only. Sits flush against the load surface and allows the bolt to resist angular loads up to 45°.
Thread
Machine-cut thread that must match the tapped hole exactly. Tapped hole must be deep enough for full thread engagement. Cross-threading destroys the bolt.
Types — Collared vs Uncollared
| Feature | Collared | Uncollared |
|---|---|---|
| Shoulder/Collar | YES | NO |
| Vertical loads (0°) | ✔ | ✔ |
| Angular loads (up to 45°) | ✔ | ✘ NEVER |
| Collar sits flush | Must sit flush against surface | N/A — no collar |
Critical Rule
- UNCOLLARED eyebolts must ONLY be loaded vertically (0°)
- Any angular load on an uncollared eyebolt causes bending of the shank and catastrophic failure
- If the sling angle is not perfectly vertical, you MUST use a collared eyebolt
Common Exam Question
“Can an uncollared eyebolt accept angular loads?” — The answer is always NO. Uncollared eyebolts can only accept vertical (0°) inline loads. Any angular force bends the shank because there is no shoulder to resist it.
WLL Reduction — Collared Eyebolts (AS 2317)
When a collared eyebolt is loaded at an angle from vertical, the WLL reduces significantly. Per AS 2317.1:2018, these loading factors apply to collared eyebolts only:
| Angle from Vertical | Loading Factor | Example (10t rated) |
|---|---|---|
| 0° (vertical) | 1.00 (100%) | 10.0 t |
| 30° | 0.50 (50%) | 5.0 t |
| 60° | 0.25 (25%) | 2.5 t |
| > 45° | PROHIBITED | — |
Always Check Manufacturer Specs
- The above factors are from AS 2317.1:2018 — always refer to the manufacturer’s rated capacity table for the specific eyebolt being used
- Manufacturer load charts may differ from the standard — use the lower of the two ratings
Never Exceed 45°
- Beyond 45° the bolt is subject to lateral forces it was not designed to resist
- Uncollared eyebolts have NO angular capacity at all — vertical pull (0°) only
Installation Requirements
- Thread fully engaged: the shank must screw completely into the tapped hole with no visible threads above the surface
- Collar flush: on collared eyebolts, the shoulder must sit flat and flush against the load surface — any gap means angular loads will bend the shank
- Tapped hole depth: must be deep enough for full thread engagement — a shallow hole leaves the bolt partially unsupported
- Hole alignment: the tapped hole must be perpendicular to the load surface
- No packing or washers: do not use washers or packing between the collar and the surface — the collar must bear directly
- Correct thread size: the bolt thread must match the tapped hole exactly — never force a mismatched bolt
- Orientation: the eye must be aligned in the direction of the sling pull — side loading on the eye plane reduces capacity
Correct Installation Checklist
- Collar sits flush against surface (no daylight gap)
- No visible threads above surface
- Eye aligned in direction of pull
- Bolt hand-tight then torqued to specification
- Tapped hole clean and free of debris
Inspection & Rejection Criteria
Inspect eyebolts before every use. Remove from service if ANY of the following are found:
Reject Immediately If
- Bent shank: any visible deformation of the threaded body — indicates overload or angular loading on an uncollared bolt
- Worn eye: the ring is thinned, elongated, or shows wear grooves from shackle contact
- Cracked collar: any cracks in the shoulder indicate fatigue failure — do not use
- Damaged threads: stripped, cross-threaded, or corroded threads prevent full engagement
- Corrosion: pitting, rust, or surface degradation reduces load capacity
- No markings: missing or illegible WLL marking, grade, or manufacturer identification — cannot verify rating
Good Condition Indicators
- Shank straight with no bends or deformation
- Eye round and uniform with no wear grooves
- Collar intact with no cracks or chips
- Threads clean, sharp, and undamaged
- WLL and grade markings clearly legible
- No corrosion or surface pitting
Applicable Standards
| Standard | Title |
|---|---|
| AS 2317 | Collared eyebolts |
| AS 4991 | Lifting equipment |
| AS 2550 | Cranes, hoists and winches — Safe use |
Key Principle
When in doubt, use a collared eyebolt — it covers all load directions within limits
Storage & Handling
- Store in a dry location — protect threads from moisture and corrosion
- Apply light oil or anti-corrosion spray to threads before storage
- Do not drop or throw eyebolts — impact can cause invisible micro-cracks
- Keep thread protectors on when not installed
- Store separately from other hardware to prevent thread damage
- Tag and quarantine any eyebolt that has been overloaded, even if it appears undamaged
- Never re-use an eyebolt that has been bent and straightened — metal fatigue makes it unsafe
- Record inspection results and maintain a register of eyebolts in service