Starrett 27-24 Firm-Joint Inside Calliper, 24"/600 mm Leg Length

The Starrett 27-24 improved firm-joint inside calliper has a leg length of 24” (600 mm) but opens to approximately one-third larger than the leg length. The joint allows for tension adjustment, while the tension will not change if the legs move. The legs are made from a high-grade steel and are ruggedly constructed and well-finished. Callipers measure the distance between two opposing sides of an object. They make inside, outside, depth or step measurements, according to their type. Callipers are commonly used in architecture, metalworking, mechanical engineering, machining, manufacturing, carpentry and medicine. The simplest callipers have two legs to mark the two points and require a ruler to take the measurement. More complex callipers use two sets of jaws instead of legs and have up to two graduated scales. Vernier, dial and digital callipers give direct and accurate readings and are functionally identical, having a calibrated scale with a fixed jaw and another jaw with a movable pointer that slides along the scale. The Vernier calliper has a scale sliding parallel to the main scale for an additional, fractional reading to improve measurement precision. The dial calliper has a circular dial with a pointer on a toothed gear rack replacing the second Vernier scale. As with the Vernier, this second measurement is added to the reading from the main scale to obtain the result. The dial calliper is used also for measuring size differential between two objects. The digital calliper takes the same sort of differential measurements as the dial calliper by zeroing the display at any point along the slide with an LCD (replacing the dial) that displays a single, easily read value in both English and metric units. Some digital callipers can hold data readings between measurements and send them to data collection devices.