Specifies international requirements for circular steel flanges in nominal pressure designations, PN 10 to PN 420. Types of steel flanges, their facings, dimensions, tolerances, threading, bolt sizes, flange face surface finish, marking, testing and inspection are specified. Guidance on pressure/temperature ratings for flanges of nominated materials are given in an Annex. This Standard is identical with and has been reproduced from ISO 7005-1:1992.