BS 970-2:1988 pdf download.Specification for wrought steels for mechanical and allied engineering purposes – Part2:Requirements for steels for the manufacture of hot formed springs.
This Part of BS 970 specifies requirements for steelmaking, chemical composition, physical properties, dimensional tolerances and testing procedures for hot-rolled flats and rounds and drawn or turned (or peeled) or ground rounds for the production of hot formed and heat treated springs The requirements apply to eleven grades of stee supplied to restricted chemical analysis ranges and twelve grades of steel supplied to hardenability limits.
Special ordering options, to be called up, as required, by the purchaser, are included appendix A.
NOTE The titles of the publications referred to in this standard
are listed on the inside back cover.
3 General
The steel products shall comply with the general requirements of this standard and with the specific requirements applicable to the grade concerned. Where any of the options given in appendix A are called up at the time of the enquiry and order, the steel products shall, in addition, comply with the requirements of any such options.
6 Chemical composition
6.1 Composition ranges
The chemical composition of the steel, based on cast analysis, shall comply with the requirements of the appropriate material specification in Table 1 or Table 2. See also option A.2.
NOTE 1 Table 2 gives the composition ranges for the steels in Table 7.
NOTE 2 The recommended maximum section thickness for each of the steel grades is given in appendix B.
6.2 Residual elements
Elements not quoted in the relevant material specification shall not be added to the steel other than for the purpose of finishing the heat.
Percentages of elements up to the limits given in Table 3 shall be considered as residual.BS 970-2:1988 pdf download.