This standard is included in DIN Handbook 403. Applies to seamless circular tubes and pipes (hereinafter briefly referred to as 'tubes') made of unalloyed steels as listed in Table 2. These tubes are predominantly used in the construction of chemical plant, vessels, pipework and for general mechanical engineering purposes. The maximum permissible working pressure and permissible working temperature are specified in Table 1. (The upper yield stress values for tubes at temperatures up to 300 degree C are specified in Appendix A).