“Measure twice, cut once,” is a phrase that is often heard in the working world. This phrase simply means that if the measurement is not correct, the cut will not matter. To minimize the chance of a “bad cut”, the development of precision measuring instruments came about. These tools provide a very precise measurement to allow a reading in the thousandths of an inch or millimeter. Precision measuring tools can be used for detailed measurements of inside diameter, outside diameter, roundness, surface finish, lengths, and depths.