Features: meets the performance requirements of federal specifications ff-t-791b, type 1, form 1, class 8, and astm f-1145, except for those provisions required of the contractor end fittings are quenched and tempered or normalized, bodies heat treated by normalizing hot-dip galvanized steel turnbuckle eyes are forged elongated, by design, to maximize easy attachment in system and minimize stress in the eye–for turnbuckle sizes 1/4″ through 2-1/2″, a shackle one size smaller can be reeved through eye forged jaw ends are fitted with bolts and nuts on size 1/4″ – 5/8″, and pins and cotter on sizes 3/4″ through 2-3/4″ modified unj thread on end fittings for improved fatigue properties, body has unc threads turnbuckles recommended for straight or in-line pull only lock nuts available