1.1 This specification covers swaged welded, cast, or forged turnbuckles with and without jam nuts. 1.2 A turnbuckle is an internally threaded loop or sleeve intended for assembly with a threaded stud, eye, hook, or jaw a This specification covers swaged welded, cast, or forged turnbuckles with and without jam nuts. A turnbuckle is an internally threaded loop or sleeve intended for assembly with a threaded stud, eye, hook, or jaw at each end, used for applying tension t