Rigging is the often-overlooked side of crane safety — the cranes get the regulatory attention, but the slings, hooks, shackles, and below-the-hook devices are inspected by the same standards (and fail at higher rates due to wear). ASME B30.9 (slings), B30.10 (hooks), B30.20 (below-the-hook lifting devices), and B30.26 (rigging hardware) define the inspection rules. This guide consolidates them.
The Three Rigging Inspection Types
Daily / Pre-Use Inspection
Performed by the user (rigger or operator) before each use. Visual inspection for cuts, kinks, missing tags, broken wires, severe abrasion, chemical damage, missing hook latches, distorted hardware. No documentation required, but findings must be acted on before use.
Frequent Inspection
Performed by a competent person at intervals tied to use frequency — daily for severe service, weekly to monthly for normal service. ASME B30.9 retirement criteria are applied. No formal documentation required at this tier in some jurisdictions, but most quality programs document frequent inspection findings.
Periodic Inspection
Documented inspection by a designated person at intervals not exceeding 12 months for normal service, more frequently for severe or special service. Records must include sling identification, inspector, date, conditions found, and disposition (in service / removed from service).
Synthetic Web Sling Retirement Criteria (ASME B30.9)
- Missing or illegible tag.
- Acid or caustic burns.
- Melting, charring, or weld spatter.
- Holes, tears, cuts, or snags exceeding manufacturer limits.
- Broken or worn stitching in load-bearing splices.
- Knots in any part of the sling.
- Excessive abrasive wear.
- Distortion, excessive pitting, corrosion, broken stitching, or fittings broken / damaged.
- Inserts (cores) showing through outer cover.
- UV degradation evidence.
Round Sling Retirement Criteria
- Missing or illegible tag.
- Cuts, holes, tears, or snags exposing the inner core yarns.
- Acid, caustic, or chemical damage.
- Heat damage, melting, charring, or weld burns.
- UV degradation.
- Distortion of fittings.
- Knots.
Wire Rope Sling Retirement Criteria
- 10 randomly distributed broken wires in one rope lay, or 5 broken wires in one strand in one rope lay.
- Severe localized abrasion or scraping.
- Kinking, crushing, bird-caging, or other damage distorting wire rope structure.
- Evidence of heat damage.
- End attachments cracked, deformed, or worn.
- Hooks with cracks, deformation, or throat opening greater than 15 percent above original.
- Severe corrosion.
Alloy Steel Chain Sling Retirement Criteria
- Missing or illegible tag.
- Cracks, breaks, gouges, or excessive nicks in chain links.
- Twisted, bent, or deformed links.
- Stretch beyond manufacturer wear limits (typically 5 to 10 percent).
- Excessive wear at link bearing surfaces.
- Heat damage discoloration.
- Hooks with cracks, deformation, throat opening 15 percent above original, or twist 10 degrees from plane.
Rigging Hardware (ASME B30.26)
- Shackles: missing or illegible tags, cracks, deformation, missing pins, bent / twisted / pitted.
- Eyebolts: cracks, deformation, missing tags, thread damage.
- Hooks: cracks, deformation, throat opening greater than 15 percent above original, twist over 10 degrees, missing latch.
- Turnbuckles: bent, cracked, deformed.
- Wire rope clips: missing, loose, corroded.
Rigging Inspection Documentation
- Sling / hardware ID (manufacturer’s tag, asset tag).
- Inspection date and inspector name.
- Inspection type (frequent / periodic).
- Condition / observations.
- Disposition: in service / removed from service.
- Re-inspection date.
3P Safety Inspections — Rigging Inspection Services
3P Safety Inspections performs ASME B30.9 / B30.10 / B30.20 / B30.26 rigging inspections nationwide. Each scope is quoted in writing, based on item count and site access. Reports include severity classification, photos, and removal-from-service documentation. Schedule a rigging inspection.
B30.9 Sling Inspection Reference
ASME B30.9 governs inspection, use, and removal-from-service for slings: alloy steel chain, wire rope, metal mesh, synthetic rope, synthetic web, and synthetic round slings. Each sling type has its own chapter (9-1 through 9-7) with specific removal criteria. Inspection categories: initial inspection upon receipt, frequent inspection before each shift, periodic inspection at service-determined intervals.
Common removal-from-service criteria: missing or illegible identification tags (every sling must have a tag with rated capacity, length, manufacturer, materials), broken wires or yarns exceeding allowable limits, kinking, crushing, birdcaging or other structural distortion, evidence of heat damage (typically 200°F+ for synthetics, visible discoloration on metal), corrosion or pitting affecting load-bearing capacity, damaged or unreadable fittings. OSHA 1926.251 incorporates ASME B30.9 by reference.
Sling Selection and Inspection Workflows
Selecting the right sling starts with load weight, geometry of the load (rigid, flexible, fragile, sharp edges), hitch type required (vertical, choker, basket, bridle), and environmental conditions (temperature, chemical exposure, UV, abrasion). Each sling type has strengths and weaknesses. Synthetic web is inexpensive, easy to inspect, protects load finishes but sensitive to UV/heat/cut. Wire rope is durable and high-temperature tolerant but heavy and requires frequent broken-wire inspection. Alloy chain is most durable for harsh environments but most expensive and requires chain stretch and link wear inspection. Round slings combine some advantages of web and wire rope but are difficult to inspect because the outer cover hides load-bearing fibers.
Daily pre-use inspection should cover the sling tag (capacity, length, manufacturer, material), the body for cuts/abrasion/heat/chemical damage/knots/unusual wear, the fittings for cracks/corrosion/distortion, and any safety latches for function. Inspectors should reject any sling with damage meeting removal criteria. Many production sites use color-coded inspection systems where current-month-inspected slings receive a colored zip tie or tape band; any sling without current color is automatically removed from service.
Storage practices significantly affect sling life. Synthetic slings should be stored indoors, off the floor, away from chemicals and UV. Wire rope slings should be coiled in figure-eight patterns to prevent kinking and stored on racks rather than piled. Chain slings can tolerate outdoor storage but should be coated lightly with lubricant in corrosive environments. All slings should be inspected before use after any storage period over 30 days.
Rigging Engineering for Complex Lifts
Rigging engineering applies engineering principles to lift planning for loads that exceed standard configurations. Complex lift candidates: irregular-shaped loads where center of gravity is offset, loads requiring multiple lift points to control bending moment, loads requiring tandem cranes with synchronized motion, and loads handled in temperature or chemical environments outside normal sling ratings.
A rigging engineer reviews load drawings, determines lift point locations and forces, specifies sling type/capacity/length, calculates sling angles to ensure forces remain within rated capacity, verifies hook block and headache ball capacity, and produces a sealed lift plan that the lift director executes. For very complex lifts the engineer may be present to verify field execution matches plan.
Cost of rigging engineering is typically $1,500-$8,000 per lift plan for typical complex lifts, scaling higher for tandem lifts and lifts over operational facilities where consequence analysis is required. The cost is generally a small fraction of total lift cost (crane day rate, rigging equipment, crew time) and significantly reduces risk of incident.
Procurement and Sourcing for Lifting Equipment
Sling and rigging procurement should source from manufacturers with current ASME B30.9 compliance, ASTM material specifications, and documented quality systems. Lower-cost generic slings from non-certified sources may meet appearance specifications but lack engineered capacity, traceability, and warranty that compliant slings provide. Bulk procurement from a single qualified vendor simplifies inspection, replacement scheduling, and warranty management.
Custom rigging assemblies — for specific load configurations or unusual lift requirements — should be designed by qualified rigging engineers and fabricated by certified shops. Custom assemblies receive their own ASME B30.9-compliant identification tag and must be inspected on the same schedule as production slings. Custom assemblies are not transferable between projects without re-rating.
Sling retirement programs should be planned and budgeted rather than reactive. Most operations retire slings on a calendar basis (annually or biannually) regardless of visual condition, because synthetic slings degrade from UV and chemical exposure. Budget approximately 15-30% sling replacement per year for active operations with synthetic slings, lower for chain and wire rope.
Frequently Asked Questions
How often must slings be inspected?
Pre-use before each shift by competent person; periodic at service-determined intervals (monthly for severe service, annual for normal service minimum). All synthetic slings should be inspected before each use due to UV degradation.
Are inspection records required for individual slings?
OSHA requires documentation for periodic inspections (not pre-use). Each sling should have unique identifier (tag, serial number, RFID) and record of inspection date, inspector, findings, disposition.
When must damaged slings be destroyed?
Any sling removed from service due to non-repairable damage must be destroyed (cut into multiple pieces) to prevent reuse.
Can damaged slings be repaired?
Synthetic web and round: no repair permitted. Wire rope: yes by original manufacturer or qualified repair facility. Chain: yes by manufacturer following original specifications. Repaired slings must be proof-tested before return to service.
Need your rigging inspected? 3P Safety Inspections handles rigging and sling inspection to ASME B30.9.