End fittings are Quenched and Tempered, bodies heat treated by normalizing. Hot Dip galvanized steel. Turnbuckles eyes are forged and elongated, by design, to maximize easy attachment in system and minimize stress in the eye. For turnbuckles size 14" through 2-12", a shackle one size smaller can be reeved through eye. Forged jaw ends are fitted with bolts and nuts for 14" through 58", and pins and cotters on 34" through 2-34" sizes. Modified UNJ thread on end fittings for improved fatigue properties. Body has UNC threads. Crosby products meet or exceed all requirements of ASME B30.26 including identification, ductility, design factor, proof load and temperature requirements. Importantly, Crosby products meet other critical performance requirements including fatigue life, impact properties and material traceability, not addressed by ASME B30.26 TURNBUCKLES RECOMMENDED FOR STRAIGHT OR IN-LINE PULL ONLY. Lock Nuts available for all sizes. Fatigue Rated.