Defines the conditions (materials, performance characteristics, temperature-related requirements) to be met for the flexible metal hoses, without coating (as defined in ISO 7369:1983, 4.1.10). The metal hoses defined are manufactured from helically wound preformed strip, generally with a right-hand lead where the turns, with or without packing, are connected together by single or double overlapping. Flexibility is achieved by adjacent turns sliding on each other.