Extension Spring Ultra Precision High Carbon Steel Plain End Type Full Twist Loops Overall Length 2 1/4 In Outside Dia 0.500 In Wire Dia 0.063 In Load 18.80 Lbs Deflection @ Load 1.40 In Initial Tension 1.70 Lbs Spring Rate 12.20 Lbs/In Meets/Exceeds ASTM A228 and AMS 5112 Package 3