Shackle Inspection Guide: ASME B30.26 Pre-Use & Periodic Checks
Before every lift: check that the WLL marking is legible, the pin is fully seated and secured, and there are no cracks, deformation, heat marks, or deep corrosion pits. Fail on any one criterion — remove from service immediately.
Pre-Use Inspection Checklist (Before Every Lift)
| CHECK ITEM | PASS | REJECT |
|---|---|---|
| WLL marking | Legible, complete, matches lift plan | Worn off, missing, or illegible |
| Bow / body | No cracks, no visible deformation | Any crack, bend, or corrosion pit |
| Pin | Straight, threads intact | Bent > 10°, damaged threads |
| Pin security | Fully seated and moused / nut + cotter fitted | Not fully threaded in, no mousing |
| Cross-section | No significant wear (< 5% reduction) | Wear exceeds 10% of cross-section |
| Heat damage | No heat discoloration (blue/black) | Any visible discoloration or charring |
Periodic Inspection (Monthly / Scheduled)
Beyond the pre-use visual, ASME B30.26 requires a more thorough periodic inspection for frequently used hardware. Frequency depends on service intensity and environment.
- 1 Clean thoroughly
Remove all dirt, grease, and corrosion products before inspection — debris can conceal cracks and pitting.
- 2 Measure critical sections
Use calipers to measure pin diameter and bow cross-sections at wear points. Compare to manufacturer specs. Reject if reduced > 10%.
- 3 Inspect threads
Check pin and body threads for wear, cross-threading, or corrosion. A pin that will not seat fully must be replaced.
- 4 Functional test
Manually thread pin in and out. It should turn smoothly with no binding or rough spots. No excessive play when fully seated.
- 5 Document
Record inspection date, inspector, findings, and disposition. Retain records for at least 12 months or per applicable safety management system.
Calculate the shackle WLL you need for your lift
Shackle Size Calculator →Frequently Asked Questions
How often should shackles be inspected?
ASME B30.26 requires a pre-use visual check before every lift. Frequent-service equipment (used every shift) needs a more thorough periodic inspection monthly. Inspect immediately after any event involving shock loading, exposure to corrosive agents, or suspected damage.
What do I do if I find a crack in a shackle?
Remove it from service immediately. Any visible crack is a direct rejection criterion under ASME B30.26. Do not attempt to repair shackles by welding, grinding, or heat straightening — a cracked shackle must be discarded.
How much pin bend is acceptable before rejection?
ASME B30.26 states that a shackle should be removed from service if the pin or bow shows a bend or distortion greater than 10° from its original axis. In practice, any visually apparent deformation warrants rejection.
Can I use a shackle with no WLL marking?
No. ASME B30.26 explicitly requires shackles to be marked with their WLL. A shackle whose WLL marking has become illegible must be removed from rigging service and not returned until re-marked by the manufacturer or retired.
Is a corroded shackle still safe to use?
Surface rust that cleans off with no visible pitting or cross-section reduction is generally acceptable. Reject any shackle with corrosion pits deeper than approximately 1 mm, or where more than 10% of the cross-section appears reduced. Use stainless or hot-dip galvanized shackles in marine or chemical environments.
Based on published standards data. Not a substitute for qualified rigger judgment. Always verify with manufacturer data.