ISO 26304:2011 specifies requirements for classification of solid wire electrodes, tubular cored electrodes, and electrode-flux combinations (the all-weld metal deposits) in the as-welded condition and in the post-weld heat-treated condition for submerged arc welding of high strength steels with a minimum yield strength greater than 500 MPa or a minimum tensile strength greater than 570 MPa. One flux can be tested and classified with different electrodes. One electrode can be tested and classified with different fluxes. The solid wire electrode is also classified separately based on its chemical composition.

ISO 26304:2011 is a combined specification providing for classification utilizing a system based upon the yield strength and average impact energy of 47 J for the all-weld metal, or utilizing a system based upon the tensile strength and average impact energy of 27 J for the all-weld metal.

a) Clauses, subclauses and tables which carry the suffix letter "A" are applicable only to solid wire electrodes, tubular cored electrodes and the all-weld metal deposits classified to the system based upon the yield strength and the average impact energy of 47J for the all-weld metal obtained with electrode-flux combinations in accordance with ISO 26304:2011.

b) Clauses, subclauses and tables which carry the suffix letter "B" are applicable only to solid wire electrodes, tubular cored electrodes and the all-weld metal deposits classified to the system based upon the tensile strength and the average impact energy of 27 J for the all-weld metal obtained with electrode-flux combinations in accordance with ISO 26304:2011.

c) Clauses, subclauses and tables which do not have either the suffix letter "A" or the suffix letter "B" are applicable to all solid wire electrodes, tubular cored electrodes and electrode-flux combinations classified in accordance with ISO 26304:2011.

For comparison purposes, some tables include requirements for electrodes classified in accordance with both systems, placing individual electrodes from the two systems, which are similar in composition and properties, on adjacent lines in the particular table. In a particular line of the table that is mandatory in one system, the symbol for the similar electrode from the other system is indicated in parentheses. By appropriate restriction of the formulation of a particular electrode, it is often, but not always, possible to produce an electrode that can be classified in both systems, in which case the electrode, or its packaging, may be marked with the classification in either or both systems.