To ensure an accurate measurement of the diameter of a wire rope, always measure the rope at three places at least 5 feet apart. Use the average of the three measurements as the diameter of the rope.

Wire Rope Safe Working Load
The term safe working load (SWL) of wire rope means the load that can be applied and still obtain the most efficient service and also prolong the life of the rope. For the safe working load of wire rope, refer to the manufacturer's certification of published breaking strength or the actual breaking strength of a piece of wire rope taken from the reel and tested.

Wire Rope Failure
Some of the common causes of wire rope failure are the following:

Using incorrect size, construction, or grade
Dragging over obstacles
Lubricating improperly
Operating over sheaves and drums of inadequate size

Overriding or cross winding on drums
Operating over sheaves and drums with improperly fitted grooves or broken flanges

Figure 6-38.- Correct and incorrect methods of measuring wire rope.

Jumping of sheaves
Exposing to acid or corrosive liquid or gases
Using an improperly attached fitting
Allowing grit to penetrate between the strands promoting internal wear

Subjecting to severe or continuing overload
Using an excessive fleet angle