A close-coiled helical extension spring, with ends fastened together to form a circle, designed to impose compression stresses toward the center of the circle thus formed when uniformly expanded.
NSN 6220-01-467-9608
NSN 6240-00-163-5143
NSN 5930-01-341-4833
NSN 4140-01-400-3610
NSN 5975-01-076-0541
NSN 5999-01-398-1145
NSN 5990-00-518-0684
NSN 6620-00-431-3837
NSN 5920-00-922-4906
NSN 4140-01-012-2460
NSN 6610-00-209-4372
NSN 6130-01-150-0783