Compression Spring Heavy Duty Color Dark Gray Music Wire Finish Plain Overall Length 1/2 in Outside Dia 5/16 in Wire Type Round Wire Dia 0.040 in End Type Squared and Ground Large Outside Dia 0.360 in Small Outside Dia 0.125 in Compressed Length 0.275 in Deflection @ Load 0.18 in Spring Rate 54 lb./in Meets/Exceeds ASTM-A228 AMS 5112 Package Quantity 10