Extension Spring Ultra Precision 302 Stainless Steel Plain End Type Full Twist Loops Overall Length 2 In Outside Dia 0.500 In Wire Dia 0.045 In Load 6.52 Lbs Deflection @ Load 2.61 In Initial Tension 0.61 Lbs Spring Rate 2.26 Lbs/In Meets/Exceeds ASTM A313 and AMS 5688 Package 3