By Lim Xu, Export Manager
Yes, most running wire rope should be lubricated throughout its service life. The lubricant applied at the rope factory protects it in transport, storage and early use, but it will not last the full life of the rope. There are two clear exceptions, which are very dusty duty and ropes that hardly flex.
Why does running wire rope need lubrication?
A wire rope works like a machine with many moving parts. A typical 6 x 47 IWRC rope has 343 individual wires that move against each other as the rope is loaded and wrapped around a drum. That movement wears the wires, mostly inside the rope where you cannot see it.
Corrosion does more damage than abrasion and usually starts with a lack of lubrication. It reduces tensile strength, impact resistance and flexibility, and it often begins internally. A US Army Corps of Engineers manual notes that the correct lubricant can extend wire rope fatigue life significantly, by 200 to 300 percent, based on tests on dry and lubricated rope.
Is the factory lubricant enough?
No. Rope makers usually force lubricant into the core during manufacture, and that treatment is generally adequate for transport, storage and a short period after installation. Under load, tension and drum pressure push the internal lubricant to the surface, where it is wiped or washed off.
Periodic cleaning and relubrication are therefore usually necessary. The same Corps manual covers the selection, installation and maintenance of wire rope and fittings. Rope distributors note the same pattern in the field, where corrosion of outer and inner wires points to lubrication that was missing or unsuitable. For cranes and hoists, ISO 4309 sets general principles for rope care, maintenance, inspection and discard.
Questions about a model or a test? Email Amy Zhao, Export Manager, at [email protected].
When should wire rope not be lubricated?
Unless the rope maker recommends it, rope working in extremely dirty or dusty conditions should not be lubricated. Abrasive dust can combine with the lubricant into a grinding compound that speeds up wear.
The second exception is rope in fairly static duty. Corps of Engineers experience is that ropes with little flexing or winding should not be lubricated, because lubricant can trap moisture in the voids between wires. Infrequent lubrication is the worst case. It leaves bare areas that form corrosion cells and deep pits, while frequent lubrication tends to keep any pits shallow.
Stainless steel is not an exception on its own. If a stainless rope flexes and winds around a drum often, it should still be lubricated.
What should a wire rope lubricant do?
The lubricant has to reach the core and protect the outside at the same time. The Corps of Engineers lists several qualities, including the ones below.
- A viscosity low enough to penetrate to the core and lubricate individual wires and strands.
- A film on the external surfaces that reduces wear against drums and sheaves.
- Protection against external corrosion, with enough adhesive strength to resist washout.
Site conditions narrow the choice further. A clear lubricant may be needed where ropes must be inspected often, and hot weather can liquefy a normal lubricant. Special environmental rules may also limit which products you can use.
How is lubricant applied to wire rope?
Cleaning comes first, because old lubricant and debris block the valleys between strands. Ropes can be cleaned with a stiff wire brush dipped in solvent, with compressed air or with superheated steam. New lubricant is then applied by continuous bath, dripping, pouring, swabbing, painting or spray nozzle.
Surface methods rely on the lubricant working its way inward. A pressure lubricator instead seals around the moving rope and drives lubricant between the strands, as our article on how a cable lubricator works explains. You can compare our wire rope lubricator models.
Frequently asked questions
How often should wire rope be inspected?
As often as the rope duty and your local rules require. Periodic inspection by a competent person is commonly set at least every 12 months, with records kept. Reduce the interval when a rope cannot be lubricated or works in corrosive conditions.
Does lubricating a rope replace inspection?
No. Lubrication slows wear and corrosion, but internal damage can still develop. Keep inspecting the rope against the discard criteria that apply to your equipment.
Talk to our factory team
We sell direct from our factory, so you work directly with our factory team. Questions about a model or a test? Email Amy Zhao, Export Manager, at [email protected].