Hydraulic tube connectors DIN 2353

  • Hydraulic tube connectors


DIN 2353 pipe fittings are supplied in two material versions::

  • carbon steel (zinc-plated or phosphate-coated) standard seal: NBR rubber,
  • stainless steel (AISI 316) standard seal: Viton

Working temperature

Allowable working temp. depends on the material of a connector and seal:

  • carbon steel:
from -40°C up to +120°C
  • carbon steel + NBR:
from -35°C up to +100°C
  • stainless steel:
from -35°C up to +100°C
  • stainless steel + Viton:
from -20°C up to +200°C

Working Pressure

The max. working pressure (nominal pressure) of DIN 2353 pipe fittings differs according to the type (light series, heavy series), size (pipe outside diameter), material and manufacturer. In the table below, data from different producers showing different types of fittings, made of carbon and stainless steel, is collected. It facilitates preliminary selection. If the required working pressure exceeds the value in the table, please contact TUBES INTERNATIONAL® Technical Department..

seriespipe O.D.[mm]maximum working pressure [bar]
for connection with
cutting ring according
to PN-ISO 8434-1
for complete fitting
according to different producers
LL4 ÷ 8100
L6 ÷ 15250160400
18 ÷ 22160100315
28 ÷ 42100100250
S6 ÷ 12 (14)630400630
16 ÷ 25400250400
30 ÷ 38250250315

Nominal pressure (max working pressure) given by manufacturers is calculated within static working conditions, the safety factor of 4 for the cutting ring connection. For fittings with metal to metal seal and BANJO fittings, the safety factor varies from 1.5 to 2.5. When choosing a fitting, dynamic pressure load and vibrations in the installation should be also considered.
For temperatures above +100°C, the max. working pressure may require reduction (contact TUBES INTERNATIONAL® Technical Department).


Pipe fittings according to DIN 2353 can be used to transfer a wide range of fluids and gases. However, the compatibility of the medium with fitting material and seal type must be always checked. For all applications different from standard hydraulic oils, please contact TUBES INTERNATIONAL® Technical Department.

Pipes used in installations

Pipes used for the construction of installations:

  • seamless steel precision pipes, protected against corrosion (phosphate-coated, zinc-plated), annealed,
  • stainless steel precision pipes, cold-drawn, free of annealing scale, heat treated (annealed).

Pipe dimensions (outside diameter, wall thickness) should be chosen according to the required flow rate and working pressure in an installation.

A complete connection of a pipe with a hydraulic installation requires: a fitting (1), a cutting ring (2), a nut (3) and a hydraulic precision pipe (4). During assembly, sharp edges of the ring (5 and 6) bite into the pipe according to the 24° cone (7) and creating a “shoulder” (9). The pipe, cut straight at 90° angle, must be pushed firmly against the bottom of the seat (10). Otherwise, the cutting ring does not bite into the pipe deep enough to create a tight connection.

złączki hydrauliczne DIN 2353
łączniki DIN 2353 do rur hydraulicznych
before assembly after assembly

The fittings manufactured according to DIN 2353, depending on their usage and pressure, can be divided into the
following categories:

  • LL (extra light series) – used in small hydraulic and cooling devices, for plastic hoses, compressed air, propane,
  • L (light series) – used for standard applications within the working pressure of that range.
  • S (heavy series) – used for higher pressure, hydraulic high pressure applications such as: hammering, shipbuilding, mining, chemical industry, heavy equipment.
VOSS DIN 2353 threaded connection range includes cutting ring connections, soft seal connections, BV10 connections, specialist assembly tools and accessories. As standard, all products are protected against corrosion with premium zinc-nickel coating VOSS Coat (CrVI chromium-free coating). Salt spray tests conducted according to DIN EN ISO 9227 proved that the basic material withstands over 1000 hours in typical working conditions with no signs of corrosion.

Comparative test in a salt spray chamber after 720 hours.
DIN 2353 fittings
hydraulic connectors DIN 2353
standard zinc coatingVOSS Coat zinc-nickel coating

Optimised construction of DIN 2353 connections

All components of VOSS connection system are perfectly matched to each other. Thus, it takes less effort to assemble the elements and they do not wear so much. Main advantages:

  • reduction of a final assembly angle from 90° to 30°
  • significantly less effort
  • easy final assembly in limited space
  • protection against excessive tightening during final assembly
  • suitable for repeated assembly

An assortment of hand tools and fully automatic machines has been developed for mounting DIN 2353 VOSS connection components. To select the correct solution, please contact Tubes International.

montage tools DIN2353

VOSS RingM cutting ring connectionsM

VOSS RingM cutting ring allows an easy, quick and reliable connection. Improved cutting geometry ensures superb tightness. Construction reinforced in all areas exposed to high pressure impact increases stability and pressure resistance. Patented limit stop enables correct pre-assembly , prevents over-tightening or under-tightening of a connector. Cutting ring, with a very thin, yet extremely hard surface obtained via the process of surface hardening, can be used for stainless steel tubes. VOSS RingM rings are coated with black VOSS Coat as standard.


  • optimum hardness to bite into the tube deep enough
  • high dynamic load capacity
  • optimum construction for correct assembly
  • slight spring-back after assembly
  • suitable for carbon steel and stainless steel tubes
VOSS RingM cutting ring connectionsM
złączka DIN 2353

ES-4 cutting ring connections

A cutting ring with a moulded seal in a recess on the cone of the ring and an additional O-ring between the ring and tube (stainless steel rings have labyrinth metal seals). The seals stop all possible leaks that may sometimes occur when the metallic seal created by the ring loosens, e.g. during continuous full load operation or operation under dynamic loads. The rings are available in both carbon steel (coated with VOSS Coat, NBR sealing) and stainless steel (with FPM/FKM sealing).


  • additional elastomer seal ideal for dynamic loads
  • reinforced ring construction can be pressed harder against 24° cone
  • slight spring-back after assembly
  • carbon steel and stainless steel versions available
DIN 2353 fittings sealing
ES-4 cutting ring connections

Formed end connection – VOSSFormSQR

 VOSSFormSQR formed end connection is a tube end formed into a shoulder matching DIN 2353 type fittings. To obtain this uniquely shaped shoulder on the tube, a section of tube material is formed with a specially designed VOSS machine (available in Tubes International). This formed tube end has and additional elastomer seal (FPM/FKM is a standard seal material).
VOSSFormSQR connection combines the highest level of safety with exceptional quality. It withstands the most extreme dynamic loads, bending and temperature fluctuations, ensuring durable and reliable connection.
VOSSFormSQR system is available in carbon steel and stainless steel.


  • outstanding resistance to dynamic loads
  • noticeable increase in torque during tightening
  • prevents over-tightening or under-tightening of a connector
  • fast connection forming process
  • perfect solution for series production
  • carbon steel and stainless steel versions available
hydraulic connection DIN 2353 VOSS
high pressure hydraulic fittings DIN 2353

BV-10 flared coupling connections

A system is suitable for operation under extreme loads. Resists bending moments, pressure variations, continuous maximum working pressure operation, vibrations and temperature fluctuations. BV-10 stub pipe is mounted in a tube end by pushing it in with VOSS manual device. The serrated surface of the stub pipe on the tube side prevents it from slipping out and acts as a metallic seal. The flared end of the tube is held in place by a clamping ring located in the nut.


  • outstanding resistance to dynamic loads
  • easy assembly, even on thick-walled pipes
  • compatible with all DIN 2353 connectors
  • suitable for stainless steel tubes
  • carbon steel and stainless steel versions available
how we connect hydraulic pipes using DIN2353 connectors
BV-10 flared coupling connections

DIN2353 Eaton Walterscheid™ connectors are designed for the most challenging applications of pipes connected
and sealed on a 24°cone. Eaton Walterscheid™ system ensures tightness of the connection up to 800 bar (for
heavy series) and 500 bar (for light series)

DIN2353 Eaton Walterscheid™ connectors made of carbon steel are plated with nickel-free, Guardian Seal™, cover to provide exceptional resistance to corrosion. The corrosion resistance of Guardian Seal™ cover exceeds the German VDMA24576 K5 standard (min. 720 hours in a salt spray chamber until red corrosion appears), qualifying the connectors for operation in the most demanding and stringent conditions. Guardian Seal™ is relatively more environment friendly. The cover is free of nickel and solvents. It meets global requirements of such European directives as RoHS (Restriction of Hazardous Substances), ELV (End-of-Life Vehicle) and REACH (Regulation for Registration, Evaluation, Authorization and
Restriction for Chemicals).

DIN2353 Eaton Walterscheid™ connector covered with corrosion resistant Guardian Seal™ is a popular solution in marine and offshore industry, for heavy duty application in agriculture, mining, railway and construction.

Three options of Eaton Walterscheid™ system are available depending on the conditions of operation:

WalPro – static operation

wall pro

A nut with a cutting ring. The profiled construction of the ring ensures optimal cut penetration and a clamp evenly distributed all around the pipe diameter. Sealing is achieved when the ring is pressed against 24° cone in a nut body during tightening. Available in stainless steel also. A complete system with a cutting ring and a nut is available only as a set marked with a code HDW-MWP…

WalRing – installation prone to vibration

A nut with a two-edge cutting ring integrated with a hardened, rubberized support ring with a special, elastomer (Viton) WALFORMplus seal. The support ring guarantees that the cutting ring properly penetrates a pipe. Reliable sealing is obtained when an elastomer seal is pressed between the pipe and the ring against 24° cone in a nut body during tightening. A complete WalRing system with rings, a seal and a nut is available only as a set marked with a code HDW-MWR…

WALFORMplus – guarantees tightness even in highly dynamic operation conditions, pressure pulsation and mechanical loads

A nut with an elastomer (Viton) seal. For the system to work, the end of the pipe must be reshaped in a special machine intended for this purpose (available at TUBES INTERNATIONAL®). A shoulder formed on the pipe with the machine and the elastomer seal do not require any additional elements such as rings to make tight connection. Reliable sealing is obtained when an elastomer seal is pressed between the shoulder on the pipe and 24° cone in a nut body during tightening. The elements of WALFORMplus system (a seal and a nut) are available only as a set marked with a code HDW-MWF…


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Type of material:

DIN 2353 tube connectors; in AISI 316 stainless steel

DIN 2353 tube connectors; in AISI 316 stainless steel

DIN 2353 tube connectors; in carbon steel (zinc-plated or phosphated)

DIN 2353 tube connectors; in carbon steel (zinc-plated or phosphated)

DIN 2353 tube connectors; with zinc-nickel coating

DIN 2353 tube connectors; with zinc-nickel coating

List of products:

Carbon steel rings and nuts

Rings and nuts

Straight connectors

Straight connectors

Angled connectors

Angled connectors

Shape connectors

Shape connectors

Screw-in straight connectors

Screw-in straight connectors

Screw-in angled connectors

Screw-in angled connectors

Carbon steel Screw-in T-connectors

Screw-in T-connectors

Screw-on connectors

Screw-on connectors

Blank plugs and caps

Blank plugs and caps

If you need help choosing a product or haven’t found the right one?

Additional information:

Video: Assembly of carbon steel DIN2353 cutting rings

See how to do it!

Video: Manual assembly of carbon steel DIN2353 cutting rings

See the video!