DIN 2353 tube fittings are used in a wide variety of fluid power applications, especially in factory, oil & gas, and construction equipment. Metric sizes from 4 to 42mm made of carbon steel or stainless steel are most prevalent. DIN (Deutsches Institut für Normung, translated as the German Institute for Standardization) metric and BSPP (British Standard Parallel Pipe) are the most common thread styles in Europe. DIN type tube fittings conform to the requirements of ISO 8434-1, DIN 2353, and DIN EN 3850 standards. This ensures interchangeability among leading brands of fittings.
DIN2353 metric fittings are available in three series of tube port end connections: tube-to-tube, tube-to-female port, and tube-to-male thread. They are also offered in three different pressure series—LL for Extra Light and intended for low-pressure applications, L for Light and used medium-pressure applications, and S for Heavy, used high-pressure applications. They are identified by measuring the thread size, pitch and the tube’s outside diameter (OD).
As with other compression-style fittings, DIN 2353 fittings consist of a body, cutting ring (ferrule) and nut. DIN connections are used in:
● Tube fittings
● Alternating valves
● Banjo and swivel couplings
● Check and non-return valves
A wide variety different configurations and threaded connections enable DIN 2353 fittings to meet many connection challenges. These flareless metric fittings are the most widely used bite-type fittings in the world. As with other compression-style fittings, DIN fittings consist of a body, cutting ring (ferrule) and nut. No O-rings or other elastomeric components are needed to provide a seal. Instead, two cutting edges of a ring (ferrule) bite into the outer surface of the tube, ensuring the necessary holding power and seal for high operating pressures and extreme vibration.
The mated sealing surfaces in DIN metric fittings and O-ring face seal fittings reduce the risk of over-tightening and provide greater reliability because of the elastomeric seal in the mating surface.
As equipment design continues requiring higher pressure ratings, OEMs are choosing DIN metric fittings more frequently. Although JIC and NPT fittings are commonly used in many applications, in many cases they are not rated for higher pressure requirements of today’s equipment, especially when high vibration occurs. Instead, more and more applications require specially-rated metric DIN connections
Both male and female versions of metric DIN 2353 24-deg cone fittings have straight metric threads. The tube OD is mated with a 24-deg seat, recessed counter-bore of the male fitting. The female mating component can be a metric DIN 2353 female tube fitting, a metric tube with a cutting ring and nut, or a 24-deg cone with an O-Ring either welded or end-formed onto metric tube. The seat angle should be measured from the fitting centerline using a 12-deg gauge. The sealing of the two components is between the 24-deg seat in the male end and the corresponding female end.
