73A-4 Starrett (4* 100mm) Yankee Spring-Type Inside Caliper with Solid Nut and Flat Legs Starrett Yankee Calipers and Dividers are made from a high-gradesteel and well-nished. The legs are made of at stock and are verydurable. The fulcrum stud is hardened and has a smooth bearingsurface. The bow spring, although exible, is exceedingly strong toassure reliability.All sizes are available with either spring nut or solid nut. The Starrettquick-adjusting automatic-closing spring nut is designed for makingfast, positive adjustments. The threads of the nut rmly engage thescrew at the slightest pressure from the leg. When the pressure iswithdrawn, the nut automatically releases itself, sliding freely over thescrew.