Extension Spring Ultra Precision High Carbon Steel Plain End Type Full Twist Loops Overall Length 2 In Outside Dia 0.500 In Wire Dia 0.045 In Load 7.50 Lbs Deflection @ Load 2.61 In Initial Tension 0.70 Lbs Spring Rate 2.60 Lbs/In Meets/Exceeds ASTM A228 and AMS 5112 Package 3