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.

1.1 This specification covers hot-coiled, heat-treated helical compression springs with tapered, closed, squared and ground ends made of hot-wrought round steel bars ³/₈ in. (9.5 mm) and larger in diameter.

1.2 This specification also serves to inform the user of practical manufacturing limits, mechanical tests, and inspection requirements applicable to the type of spring described in 1.1.

1.3 Supplementary Requirements S1 to S8 inclusive of an optional nature are provided. They shall apply only when specified by the purchaser. Details of these supplementary requirements shall be agreed upon by the manufacturer and purchaser.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.