• The designations are in accordance with the system proposed by ISO/TC 17/SC 2.
• Elements not quoted should not be intentionally added to the steel without the agreement of the purchaser, other than for the purpose of finishing the heat. All reasonable precautions should be taken to prevent the addition, from scrap or other material used in manufacture, of such elements which affect the hardenability, mechanical properties and applicability.
• In the case of the grades with specified hardenability requirements (see tables 5 to 7), except for phosphorous and sulfur, insignificant deviations from the limits for cast analysis are permissible; these deviations shall, however, not exceed in the case of carbon ± 0,01 % (m/m) and in all other cases the values according to table 4.
• For boron-treated steels, see ISO 4954.
• Steels with improved machinability by either lead additions or higher sulfur levels up to about 0,100 % (m/m) S (including controlled sulfide morphology) may be available on request.