A Double Ended Calliper with a dual purpose. The double ended calliper by Robert Sorby can be used for vessel diameters and also wall thickness. No need to remove the calliper to see the wall thickness. You can see the measurement at the external end. What one end measures the other end shows, this type of measuring device is essential when tackling hollow forms. The old adage, measure twice cut once. Supplied in two sizes 4″ (100mm) and 7″ (175mm). Note: The size is the measurement from the pivot point to the tip of the calliper.
