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 6320-00-139-1090
NSN 6220-00-793-3167
NSN 5835-00-228-9082
NSN 5855-01-484-1919
NSN 6150-00-317-5498
NSN 6145-01-341-3297
NSN 6610-01-180-2184
NSN 2925-01-270-1124
NSN 5855-00-631-4565
NSN 5996-01-319-8876
NSN 6130-00-180-5149
NSN 6135-01-521-0378