DIN 11851

In order to connect equipment where hygiene is a top priority, NES supply a range of seals and fittings which are compliant with the widely recognised DIN 11851 standard. All our products comply with key criteria, such as uniform wall thickness, tight tolerances and suitable finishes.

DIN 11851 is commonly used in fitting for the pharmaceutical, biotechnology, food, chemical and solar industries. Offering high quality fitting, they are robust, easily sterilised and cavity free. Used throughout Europe in many hygienic settings, NES supply DIN 11851 seals which are precision manufactured here in our Sheffield facility.

The DIN 11851 standard

DIN (Deutsches Institut für Normung) standards refer to a series of technical standards originating in Germany. These standards are widely used throughout Europe to ensure norms for quality control, safety, environmental protection and rationalisation.

The specification of DIN 11851 is in relation to hygienic unions, providing a standard for connections used in sanitary conditions which comply with safety and food standard regulations.

Also known as the ‘dairy thread’ DIN 11851 sanitary fittings consist of a clutch thread with coarse, rounded thread edges making it easier to clean.

Our DIN 11851 seals

Our DIN 11851 seal products are available in two variations. The flanged or lipped design provides a flush fitting and crevice free joint. The more commonly used unlipped seal creates a secure join which is robust and reliable.

Seals are typically manufactured in EPDM, although they can also be manufactured in other elastomers as required. Other common variants include nitrile rubber (NBR), Viton (FKM), and Silicone.

DIN 11851 dimensions

All DIN 11851 dimensions are fabricated according to specifications, with the exception of the welding connections. This includes thread dimensions, pipe dimensions and flanges.

For DIN 11851 seals, the recognised DN sizes are provided below:


DN size Internal Diameter

Outer Diameter

Height Radius
DN10 12 mm 20 mm 4.5 mm 2.3 mm
DN15 18 mm 26 mm 4.5 mm 2.3 mm
DN20 23 mm 33 mm 4.5 mm 2.8 mm
DN25 30 mm 40 mm 5 mm 2.8 mm
DN32 36 mm 46 mm 5 mm 2.8 mm
DN40 42 mm 52 mm 5 mm 2.8 mm
DN50 54 mm 64 mm 5 mm 2.8 mm
DN65 71 mm 81 mm 5 mm 2.8 mm
DN80 85 mm 95 mm 5 mm 2.8 mm
DN100 104 mm 114 mm 6 mm 2.8 mm
DN125 130 mm 142 mm 7 mm 3.5 mm
DN150 155 mm 167 mm 7 mm 3.5 mm

For more advice on DIN 11851 compatibility, including suitable elastomers for your process, why not contact our Sales Team today.