This European Standard describes a method for the ultrasonic-testing of uncoated flat austenitic and austenitic-ferritic stainless steel product for internal discontinuities. It is applicable to flat product in nominal thickness range of 6 mm to 200 mm. Mechanised, semi-automatic or automatic techniques may be used but should be agreed between the purchaser and the supplier.This standard also defines 3 quality classes for the flat product body (classes S1, S2 and S3) and 4 quality classes (E1, E2, E3, E4) for the edges in accordance with the criteria specified in clause 12.Other methods of testing, e.g. by transmission technique or other test equipments may be used at the manufacturer's discretion provided that they give equivalent results to those obtained under the conditions of this standard. In the event of a dispute, only the method defined in this standard prevails.Testing of flat product of thickness less than 6 mm may be the subject of special agreements between the parties concerned.