When a rope chain is worn as bling, whether it's silver, gold, platinum, or stainless steel, you might wonder just how thick the chain is. Measuring the thickness of a rope chain uses the same procedure as measuring the diameter -- the thickness -- of wire rope, only on a much smaller scale, using millimeters instead of inches. A caliper gives an instant and accurate reading of the thickness of a chain.
Open the jaws of the caliper so that the chain can fit between them.
Turn the chain so that the outermost points of the metal wires that make up the rope chain are between the jaws of the caliper and touching the jaws.
Close the jaws and read the thickness of the chain on the caliper's readout.