Extension Spring Ultra Precision High Carbon Steel Plain End Type Full Twist Loops Overall Length 3/4 In Outside Dia 0.180 In Wire Dia 0.029 In Load 5.82 Lbs Deflection @ Load 0.28 In Initial Tension 0.52 Lbs Spring Rate 18.9 Lbs/In Meets/Exceeds ASTM A228 and AMS 5112 Package 3