This part of ISO 9328 specifies the requirements for flat products for pressure equipment made of weldable fine grain steels as specified in Tables A.1 and B.1. The requirements and definitions of ISO 9328-1 also apply to this part of ISO 9328. NOTE 1 Fine grain steels are understood as steels with a ferritic grain size of 6 or finer when tested in accordance with ISO 643. NOTE 2 This part of ISO 9328 offers the possibility to specifying products in accordance with European design codes and ASME-type design codes.