Wire Rope & Cable
WIRE ROPE IS A MACHINE. Understand and respect it.
Like any machine, it needs proper care and maintenance for optimal safety and long service life. For a better understanding of wire rope, we highly recommend the Wire Rope User's Manual by the Wire Rope Technical Board.
Refer to the General Warnings Page
These warnings also apply to wire rope. Only additional warnings and information are listed below.
Rated capacity is the load which a new wire rope may handle under given operating conditions and at assumed design factor. A design factor of 5 is chosen most frequently for wire rope. (Operating loads not to exceed 20% of catalog Breaking Strength.) Operating loads may have to be reduced when life, limb or valuable property are at risk or other than new rope is used. A design factor of 10 is usually chosen when wire rope is used to carry personnel. (Operating loads not to exceed 10% of catalog Breaking Strength.)
Responsibility for choosing a design factor rests with the user.
Matching Attachment's Working Load Limit
Attachments must have at least the same Working Load Limit as the wire rope used.
Clips, sockets, thimbles, sleeves, hooks, links, shackles, sheaves, blocks, etc. must match in size, material and strength to provide adequate safety protection. Proper installation is crucial for maximum efficiency and safety.
Keep out from under a raised load.
Do not operate load over people. Do not ride on load. Conduct all lifting operations in such a manner that if equipment were to fail or break, no personnel would be injured.
Keep out from under a raised load. Do not operate loads over people and keep out of the line of force of any load.
Avoid Shock LoadsAvoid impacting, jerking or swinging of load. Working Load Limit will not apply in these circumstances because a shock load is generally significantly greater than the static load.
Inspect wire rope regularly
Use inspection instructions as guidelines only. Two of the most important prerequisites for inspecting wire rope are technical knowledge and experience.
Check the general condition of the wire. Also, look for localized damage and wear, especially at wire rope attachments. Inspect all parts that come in contact with the wire rope. Poor performance of wire rope can often be traced back worn or wrong-sized sheaves, drums, rollers, etc. Looks for kinks, broken wires, abrasions, lack of lubrication, rust damage, crushing, reduction of diameter, stretch or other obvious damage. If any of these conditions exists or if there is any other apparent damage to the wire rope, retire the wire rope according to the instructions below.
When in doubt about the extent of the damage, retire the wire rope in question immediately. Without laboratory analysis, it is impossible to determine the strength of damaged or used wire. Thus, you will not be able to tell whether wire rope with any amount of damage is safe to use. Retire the wire rope that is damaged. For specific inspection procedures check various OSHA and ANSI publications.
Destroy, Rather than Discard, Wire Rope to be Retired
Wire rope that is not destroyed might be used again by someone not aware of the hazard associated with that use. Destroying wire rope is best done by cutting it up into short pieces.
Measuring Wire Rope Diameter
Below is an illustration that displays the correct method to measure wire rope diameter.
Wire Rope Diameter Tolerances
Wire rope is always manufactured larger—never smaller—than the nominal diameter when specified in inches. The allowable tolerances are shown in the table below.
In standard practice, the nominal diameter is the minimum diameter. All tolerances are taken on the plus side when specified in inches. Wire rope is not termed oversize until its diameter exceeds the allowable maximum.
|TABLE VI. Rope Diameters for type VI small cords.|
|Rope Diameter (in)||Tolerance (in)|
Tolerances specified in Federal Specification RR-W-410-H