What DIN Means for Metric Hydraulic Fittings

DIN stands for Deutsches Institut fur Normung, the German Institute for Standardization. In hydraulic fittings, DIN often refers to metric connection styles used widely in European hydraulic and pneumatic systems.

DIN fittings are commonly associated with DIN 2353, DIN EN 3850, and ISO 8434-1. They are used in oil and gas, construction, industrial machinery, and other fluid power applications.

Where DIN Standards Appear

DIN metric connections appear in check valves, compression fittings, hydraulic hose fittings, swivel fittings, and banjo fittings. Sizes commonly range from small metric tube connections up to larger metric sizes used in heavy equipment.

Some DIN metric bite-type fittings use a 24 degree connection. Other DIN-related hose and tube standards include metric hose fittings and cone-style connections used in European equipment.

Material Options

DIN 2353 fittings are commonly made from carbon steel or stainless steel. Stainless steel 1.4571, also known as 316Ti, is used where corrosion resistance and service life are important.

Stainless steel, Monel, Inconel, and other specialty materials may be used in harsh environments such as offshore service, salt spray, saltwater submersion, acidic atmospheres, extreme heat or cold, physical shock, and vibration.

Carbon steel can also be suitable for many normal hydraulic applications. Zinc-nickel plating may be used to improve corrosion resistance, paintability, abrasion protection, temperature stability, and compatibility around stainless steel or aluminum.

Applications and Industries

DIN metric fittings are used across agricultural equipment, construction equipment, industrial machines, oil and gas systems, drilling platforms, hydropower plants, railway technology, recycling equipment, shipbuilding, machine tools, wind turbines, material handling, and mining equipment.

The key is that DIN is not a single part shape. It is a standards family used across many connection types, pressure classes, and materials.

DIN 2353 Pressure Series

DIN 2353 fittings are commonly classified into LL, L, and S pressure series. LL is for very light pressure applications. L is the light series. S is used for higher-pressure systems.

Each series should be identified by tube OD, thread size, and pitch. DIN fittings are widely used in Europe, and their use in U.S. equipment continues to grow as OEMs build machines for global markets and higher pressure requirements.