Elevator rope replacement criteria decide when steel suspension ropes are retired, mostly on condition rather than age. Ropes wear as they bend over sheaves, and inspectors look for broken wires, lost diameter, rouge and deformation. The exact limits depend on which standard or manufacturer instruction applies here. That makes the criteria worth understanding before an AMC contractor recommends new ropes.

This guide explains the four main replacement triggers and how broken wires are counted per rope lay. It clarifies a common mix-up about which standard actually sets the discard limits. It also explains why ropes are replaced as a complete matched set, not one at a time. Finally, it lists what your lift maintenance reports should record about rope condition.

When do elevator ropes need replacing?

Elevator ropes need replacing when wire breaks, diameter loss, rouge or deformation pass the applicable limits. Rope maker Prysmian groups the triggers into crown breaks, valley breaks, diameter reduction and rouge. Under ASME A17.6, a permanently kinked, bent or deformed rope must be replaced outright.

Rouge is the red dust of fretting corrosion, where wires rub and oxidise inside the rope. It points to internal wear, so the allowed number of breaks falls when it appears. Traction suspension ropes under 8 mm showing rouge must be replaced under ASME A17.6.

Quick Answer

For most lift ropes, measured condition rather than age decides retirement. Wire breaks, diameter loss, rouge or permanent deformation beyond the applicable limits mean the rope set must be replaced.

How are broken wires counted?

Broken wires are counted per rope lay, the length over which one strand makes a full turn. Prysmian puts a lay at roughly 6.5 times rope diameter, about 83 mm on a 12.7 mm rope. Inspectors count breaks in the worst lay along the rope.

ASME A17.6 allows up to 24 distributed crown breaks per lay on a six-strand rope under normal wear. That limit halves to 12 under unfavourable wear conditions or when rouge appears. Unequal breaks, four side-by-side breaks and valley breaks trigger replacement at far lower counts.

Quick Answer

Breaks are counted per rope lay, about 6.5 rope diameters, in the worst section. ASME A17.6 caps distributed crown breaks at 24 per lay for six-strand ropes in normal wear.

Which standard sets discard criteria for lift ropes?

No single worldwide rule sets discard criteria for lift ropes. ISO 4344:2022 covers the manufacture and testing of lift ropes from 6 mm to 38 mm, not their discard. Discard limits sit in documents like ASME A17.6 in North America and the Nordic SS-INSTA 730:2025.

ISO 4309 sets discard criteria too, but for cranes and other lifting appliances, not passenger lifts. EN 13015 sets rules for the maintenance instructions supplied with new lifts. In Dubai, ask your AMC contractor which criteria they apply and have that written into the contract.

Quick Answer

ISO 4344 covers lift rope manufacture, not discard, and ISO 4309 covers cranes. Discard limits come from codes like ASME A17.6 or SS-INSTA 730, so name one in the contract.

Why are lift ropes replaced as a set?

Lift ropes are replaced as a set because the ropes share the load and wear together. ASME A17.1 requires the whole set replaced when one rope wears out, except for installation damage. Replacement ropes must also match in manufacturer, material, grade, construction and diameter.

Tension matters too, since a new rope beside worn ones may carry an uneven load. Mitsubishi Electric's hoisting rope manual says all ropes should have almost equal tension. It also warns that new ropes stretch faster at first, so checks should be more frequent after replacement.

Quick Answer

Ropes share load and wear, so ASME A17.1 requires replacing the whole set with matching new ropes. Tension should then be equalised and checked more often while new ropes stretch.

What should an AMC report record about ropes?

An AMC report should record rope diameters, broken wires per lay, rouge or corrosion and any deformation. ASME A17.6 asks for two diameter measurements at right angles at the same point. Recording the location of the worst section lets the next visit compare like with like.

Rope tension, sheave groove condition and the date of the last rope change belong in the same record. Those trends show when replacement is approaching, so owners can plan rather than react. Our annual lift maintenance contract guide explains the wider maintenance task list.

Quick Answer

Each report should log diameters measured at right angles, broken wires per lay, rouge, deformation, tension and sheave condition. Comparing the worst section over time shows when replacement is near.

Frequently Asked Questions

How often should elevator ropes be replaced?
Most ropes have no fixed interval, though ropes under 8 mm also carry a manufacturer design-life limit. Plan replacement around the trend in rope readings, not just a calendar date.
What is a rope lay?
A rope lay is the length over which one strand makes a complete turn around the rope. Prysmian, a rope manufacturer, puts it at roughly 6.5 times the rope diameter.
What is rouge on a lift rope?
Rouge is red dust from fretting corrosion between wires, and it points to internal wear. Under ASME A17.6, its presence halves the allowed number of broken crown wires per lay.
What is a valley break?
A valley break is a wire that breaks between strands rather than on the outer crown. ASME A17.6 requires replacement for more than one per lay, or any with rouge.
Can one damaged rope be replaced alone?
Under ASME A17.1, a single rope may be replaced only if it was damaged during installation or acceptance testing. Otherwise, the entire set must be replaced with matching new ropes.
Do lift ropes need lubrication?
Mitsubishi Electric's manual says lubrication is normally not required, except in special environments such as hot, humid or dusty hoistways. Only designated oil should be used, to avoid traction loss.
Who decides when lift ropes need replacing?
The maintenance contractor assesses condition against the criteria named in the contract or manufacturer instructions. Owners should ask which document is used and see the measurements behind any replacement recommendation.
How is rope diameter measured?
Take two caliper measurements at right angles at the same point on each rope. Under ASME A17.6, both readings below the limit require replacement, while one triggers stricter wire-break limits.
Do new ropes need extra checks?
Yes, Mitsubishi Electric's manual warns that new ropes elongate faster soon after replacement. Inspections should be more frequent at first, with tension and runby adjusted as the new ropes settle.
Why do some lifts wear ropes faster than others?
Ropes wear faster when they pass over more sheaves and when the lift starts more often. Poor sheave grooves and unequal tension also count as unfavourable conditions under ASME A17.6.

Main Takeaways

Most lift ropes are retired on measured condition, not age: wire breaks per lay, diameter loss, rouge and deformation. ISO 4344 covers rope manufacture, so the discard criteria must come from a named code such as ASME A17.6. Worn ropes are replaced as a matched set. AMC reports should record diameters, broken wires, tension and sheave condition at every visit.

Your next step for lift rope replacement

Elevator rope replacement is a measured decision, based on broken wires, diameter, rouge and deformation. The limits depend on the code applied, and ISO 4344 is not that code. Because ropes are replaced as a set, a replacement recommendation affects the whole lift at once. Understanding the criteria helps owners judge whether a recommendation is due or simply premature.

Ask your contractor which discard criteria they use and request the measurements behind any rope recommendation. Check that reports record the worst section, diameters at right angles and tension. Our elevator modernisation guide covers when wider upgrades make more sense than new ropes alone. QSERV's elevator AMC team can review your rope records and any planned replacement before work is booked.

Sources & References

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