Wire Rope Sling Inspection Guide
How often to inspect wire rope slings, how to count broken wires, and when a wire rope sling must come out of service, based on OSHA 1910.184 and ASME B30.9. A sling that is worn or damaged can fail without warning, so a quick, consistent inspection before every use is the best protection for your crew and your load.
Safety first: Inspect every sling, with all its fastenings and attachments, each day before use, and remove damaged or defective slings from service immediately. This guide is a summary; always follow the sling manufacturer’s instructions and the current OSHA 1910.184 and ASME B30.9 requirements.
On this page: When to inspect · Who inspects · How to inspect · Removal criteria · Tags · Rejected slings · Records · FAQ
When to Inspect
ASME B30.9 sets three levels of inspection for wire rope slings.
Initial
Before first use, inspect every new, altered, modified or repaired sling to confirm it is correct, undamaged and properly tagged. No written record is required.
Frequent (daily)
Each shift, before the sling is used, do a visual check for damage. Slings in severe or special service should be checked before each use. No written record is required by ASME.
Periodic
A complete inspection of the entire sling, including splices and fittings, at least once a year. ASME guideline intervals: normal service yearly; severe service monthly to quarterly; special service as recommended by a qualified person. Document the most recent periodic inspection.
Slings in storage or sitting idle do not need periodic inspections, but if more than a year has passed since the last one, give the sling a full periodic inspection before putting it back in service.
Who Should Inspect
OSHA requires daily inspections by a competent person designated by the employer: someone trained to recognize sling damage and authorized to take a sling out of service. ASME B30.9 says inspections are performed by a designated person, and any deficiency is evaluated by a qualified person, who decides whether it is a hazard and approves any sling before it goes back into service.
How to Inspect, Step by Step
- Check the tag first: it must be present and legible and show the rated load for the hitches used. Confirm the rating suits the load and hitch.
- Lay the sling out straight in good light.
- Wearing gloves, run your hand along the full length to feel for broken wires, kinks and flat spots.
- Count broken wires within one rope lay and within each strand, and compare with the removal limits.
- Look for kinking, crushing, birdcaging, abrasion, corrosion and heat discoloration.
- Inspect the eyes, splices, sleeves and end fittings, and any hooks (remove if opened more than 15% or twisted more than 10°).
- If you find any removal condition, tag the sling “Do Not Use” and take it out of service.
Removal Criteria
Inspect the entire length, including eyes, splices, sleeves and end fittings. A rope lay is the length of rope in which one strand makes one complete turn around the rope.
Remove the sling from service if you find:
- Missing or illegible sling identification
- Broken wires: for strand-laid and single-part slings, 10 randomly distributed broken wires in one rope lay, or 5 broken wires in one strand in one rope lay. For cable-laid slings, 20 broken wires per lay. For braided slings, 20 broken wires per braid (less than eight-part) or 40 per braid (eight-part or more)
- Wear or scraping of one-third the original diameter of outside individual wires (OSHA), or severe localized abrasion or scraping (ASME B30.9)
- Kinking, crushing, birdcaging or any other damage that distorts the rope structure
- Evidence of heat damage. OSHA requires permanent removal of fiber core wire rope slings exposed to temperatures above 200°F
- End attachments or fittings that are cracked, deformed or worn
- Corrosion of the rope or end attachments
- Hooks opened more than 15% of the normal throat opening or twisted more than 10° (OSHA); see ASME B30.10 and B30.26
- Any other condition that causes doubt about continued use
Before you replace a sling, check the rating you need: see our wire rope sling capacity chart or shop wire rope slings.
Missing or Illegible Tags
Every sling must carry permanently affixed, legible identification. OSHA prohibits using a sling without it, and ASME B30.9 lists a missing or illegible tag as the first removal criterion. Without the tag, nobody can confirm the rated load. OSHA requires wire rope sling markings to show the safe working load for the hitch types used, the angle it is based on, and the number of legs if more than one.
What to Do With a Rejected Sling
- Remove it from service immediately and tag it “Do Not Use.”
- Store it apart from slings in service so it cannot be picked up by mistake.
- A qualified person decides whether the sling can be repaired. It may not return to service until a qualified person approves it.
- Repairs may be made only by the sling manufacturer or a qualified person (ASME B30.9).
- If the sling will not be repaired, destroy it so it cannot be used again.
When in doubt, take it out.If you are not sure a sling is safe, do not use it. Remove it from service and set it aside for a qualified person.
Record Keeping & Printable Checklist
- OSHA: keep proof test certificates for welded end attachments, which must be proof tested at twice their rated capacity before first use.
- ASME B30.9: keep documentation that the most recent periodic inspection was performed. Written records are not required for initial or frequent (daily) inspections, and individual inspection records for each sling are not required.
- Good practice: give every sling an ID, and log daily checks so removed slings are tracked. Our one-page printable checklist lists every removal criterion with a code and has a daily log.
Frequently Asked Questions
How many broken wires are allowed in a wire rope sling?
For strand-laid and single-part slings, remove the sling at 10 randomly distributed broken wires in one rope lay, or 5 broken wires in one strand in one rope lay. ASME B30.9 allows 20 per lay for cable-laid slings, and 20 or 40 per braid for braided slings depending on the number of parts.
What is a rope lay?
A rope lay is the length of rope in which one strand makes one complete turn around the rope. Broken-wire limits are counted within one lay.
Can a kinked or birdcaged wire rope sling be straightened and reused?
No. Kinking, crushing, birdcaging or any other damage that distorts the rope structure is a removal criterion under OSHA 1910.184 and ASME B30.9.
What temperatures damage wire rope slings?
OSHA requires fiber core wire rope slings to be permanently removed if exposed to temperatures above 200°F. For non-fiber core slings used above 400°F or below minus 60°F, follow the sling manufacturer’s recommendations.
Other inspection guides: Chain slings · Synthetic web slings · Round slings
Questions about a sling or need a replacement? Call (706) 750-9099.
Sources: OSHA 29 CFR 1910.184, Slings; ASME B30.9-2021, Slings. This guide summarizes those requirements and does not replace them.