EN ISO 15245-1
The DIN EN ISO 15245-1 defines terms, dimensions, and tolerances for cylindrical threads with nominal diameters of 30 mm (M30x2), 25 mm (M25x2), and 18 mm (M18x1.5), used for connecting valves to gas cylinders in medical, industrial, and diving sports applications. It does not include requirements for mechanical strength, gas tightness, or resistance to repeated assembly and disassembly.