DIN 7603 Sealing Rings

DIN 7603 defines standardized sealing rings and gaskets used with compression couplings and screw plugs. The current edition, DIN 7603:2001-05, specifies three principal designs: Type A flat gaskets, Type C filled gaskets, and Type D O-rings. The standard therefore covers more than the commonly searched copper flat sealing ring, although Type A is one of the most widely encountered commercial versions.

Type A is a solid flat sealing ring with a simple annular geometry. Copper, aluminium, soft iron, zinc and other specified materials are included in the standard, with material selection depending on the sealing medium, temperature and application requirements. Copper Type A rings are particularly common in hydraulic connections, screw plugs and other static joints where the relatively soft metal can conform to minor surface irregularities.

DIN 7603 sealing rings are commonly associated with screw plugs such as DIN 908 and with compression-type pipe connections. Their standardized inner diameter, outside diameter and thickness allow the sealing ring to be matched to the relevant connection size rather than selected simply as a general-purpose washer. Type C differs from Type A by incorporating a filler within a metal covering, while Type D uses an O-ring geometry and therefore represents a different sealing configuration.

For product selection, the critical factors are the DIN 7603 type, nominal dimensions, sealing material, mating connection and service conditions. A copper Type A ring should not automatically be treated as interchangeable with a Type C filled gasket or Type D O-ring, even when the nominal connection size is similar.