EN 10305-4 Steel tubes for precision applications. Part 4: Seamless cold drawn tubes for hydraulic and pneumatic power systems.
DIN 2391-1 Seamless precision steel tubes. Part 1: Dimensions.
Steel grades according to EN: E215 (1.0212), E235 (1.0308), E355 (1.0580)
Steel grades according to DIN: St 44.4, St 37.4, St 52.4
Mechanical properties in room temperature
|Steel grade||Yield limit ReH
|Tensile strenght Rm
|Elongation A min. %|
|E215||215||290 to 430||30|
|E235||235||235 to 480||25|
|E355||355||490 to 630||22|
Note. For tubes with outside diameter ≤ 30 mm and wall thickness ≤ 3 mm, minimum values of ReH are 10 MPa lower than given above.
+N (EN); NBK (DIN) Normalized (after the last cold drawing process the tubes are normalized in a controlled atmosphere)
Coarseness of the outer and inner surface (starting with ID 15 mm) Ra ≤ 4 μm
– the length of the maufactured precision tubes is 6 000 mm (tolerances at the standard length is 0+50 mm and at the exact length is 0+10 mm)
– exact length can be from the range of 3 000 mm – 9 000 mm
Total deviation: max 0,0015 L
Local deviation: max 3 mm / 1 m
Ends of the tubes
The ends of the tubes are smooth and enclosed with plastic caps.
The electromagnetic nondestructive testing of leak tightness is always performed according to EN 10246-1 or other corresponding standards. Selection of the tests is defined in EN 10305-1. The NDT test and the flattening or drift expanding test is possible.
Each tube is marked by the InkJet system along the whole length according to standards or according to customer requirements. Tube bundles are marked by tags.
– phosphated and oiled
– electrolytically galvanized and chrome-coated
The HPL tubes are delivered in bundles with either circular or hexagonal cross-section weighting maximum 2000 kilograms. The tubes are tied with a steel band. Upon agreement it is possible to protect the surface with paper lining or protect the ends of the bundle with PCV foil.
Certificates for HPL tubes
According to the following standards: EN 10 204 or DIN 50049
– nonspecified testing – 2.2
– specified testing 3.1.B or 3.1
– upon agreement – 3.1.C or 3.2
Tables of pressures for hydraulic tubes (MPa)