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
NSN 6645-00-754-4108
NSN 5915-01-626-8919
NSN 5975-01-471-3828
NSN 5910-01-314-3637
NSN 5965-01-501-5638
NSN 2925-01-065-0060
NSN 6620-00-179-9079
NSN 6240-01-386-4594
NSN 5960-00-087-6636
NSN 5920-01-401-5315
NSN 5945-01-648-2231