Extension Spring, Ultra Precision, High Carbon Steel, Plain, End Type Full Twist Loops, Overall Length 1 1/2 In, Outside Dia 0.500 In, Wire Dia 0.063 In, Load 18.80 Lbs, Deflection @ Load 0.67 In, Initial Tension 1.70 Lbs, Spring Rate 25.5 Lbs/In, Meets/Exceeds ASTM A228 and AMS 5112, Package 3