Check the listing for details. Starrett 73A-6 Yankee Spring-Type Inside Caliper, 6" Size, Solid Nut. Condition: Used, Made in United States. Listed at 54.95 USD. this is a used item see images for the exact condition of the item. Starrett 73 Series "Yankee" Spring-Type Inside Calipers with Flat Legs and Solid Nut are made from a high-grade steel and well-finished. The legs are made of flat stock and are very durable. Calipers feature a hardened fulcrum stud, strong and flexible bow string, and centrally located leg adjustment to assure smooth action. Caliper size and capacity is 6". 6” (150mm) with Solid Nut assure smooth action. Caliper size and capacity is 6". Design: A traditional, solid knurled nut that must be screwed up or down the threaded rod to adjust the divider legs. Usage: Best for precise, fine-tuning of measurements because the threads keep the setting locked in place.