1.1 This International Standard specifies requirements for four grades of heat-treated cast carbon and alloy steels for general engineering and structural purposes. 1.2 In cases where castings are produced by welding together component parts, this International Standard does not cover the welding process or the properties of the weldment. 1.3 The four steel grades are intended for service at ambient temperature. However, properties at other temperatures may be agreed on through the use of the supplementary requirements in 9.4.1 or 9.4.4 of ISO 4990:1986.