This part of ISO 9328 specifies the requirements for flat products for pressure equipment made of quenched and tempered weldable fine grain steels as listed in Tables A.1 and B.1. The requirements and definitions in ISO 9328-1 also apply to this part of ISO 9328. NOTE 1 Fine grain steels are understood to be 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 of specifying products in accordance with European design codes and ASME-type design codes.