Extension Spring Ultra Precision High Carbon Steel Plain End Type Full Twist Loops Overall Length 3 1/2 In Outside Dia 0.360 In Wire Dia 0.055 In Load 17.60 Lbs Deflection @ Load 1.77 In Initial Tension 1.60 Lbs Spring Rate 9.00 Lbs/In Meets/Exceeds ASTM A228 and AMS 5112 Package 3