This specification covers the standard for hot-coiled, heat-treated helical compression springs with tapered, closed, squared and ground ends made of hot-wrought round steel bars. Cross sections for hot-wrought round, square, and round-cornered square bars of steel of the bar diameter shall be taken into consideration when designing and calculating the solid height, spring rate, solid stress, and solid capacity. The spring shall undergo quenching and tempering to have sufficiently high hardness and withstand the stresses developed in testing. Springs with specific indentation diameter shall not exceed the specified Brinell hardness numbers. The spring shall meet the metallurgical requirement, end construction, physical requirements such as measurements, solid height, free height, loaded height, permanent set, uniformity of pitch, outside diameter and calculations of solid capacity and uncorrected solid stress.