How to Measure Rope Width

Measure a rope's width with calipers.

It's a good idea to measure the width of rope before you use it if you're unsure how long it's been in use or you're unsure of its quality. To calculate the safe working load of wire rope in tons, square the width of the rope and multiply by 8. Unfortunately, there is no formula to calculate the safe working load of fiber rope. Consult the Resources section for rope diameters and corresponding safe loads.

Things You'll Need

• Calipers
• Ruler

Instructions

1. Loosen the locking screw on your calipers and open the caliper's jaws wider than the width of your rope.

2. Close the jaws of the calipers around the widest diameter of the rope. Close the jaws gently; do not push them into the rope.

3. Tighten the locking screw on the calipers again and remove them from around the rope.

4. Read the measurement beside the bottom jaw of the calipers if your calipers have labeled measurements. This measurement is the width of your rope. Continue to Step 5 if your calipers do not have labeled measurements.

5. Place your ruler between the two jaws of your calipers and read the measurement.

References

• Rigging.net: Wire Rope
• Mac Whyte: How to Measure Wire Rope Diameter (PDF)
• Tresna: How Use and Read Calipers

Resources

• EngineeringToolbox.com: Fiber Rope - Strength