- EN 10305-1

 - EN 10305-4

 - EN ISO 286-2

 Used for - Hydraulic cylinders 

TMK HYDRA ART identification        

TMK Hydra  ArtH xxx  OD x ID / TMK Hydra  ArtH xxx  OD x ID –IFR

TMK Hydra is the TMK-Artrom classification of Cold drawn inside skived and roller burnished (SRB) tubes.

Art H xxx is the grade identification, xxx being the minimum granted yield point in Mpa.

OD, ID are outside and inside diameters nominal values. 

IFR - Improved Fatigue Resistance – is an optional finishing which increase the Fatigue resistance on cycling stress specific for hydraulic cylinders use. 

Size program according Table 1 (Intermediate sizes can be produced subject of agreement before ordering). 


 - Outside Diameter (OD) in accordance with EN 10305-1

  - Inside Diameter (ID) in accordance with ISO H8 – EN ISO 286-2, Ra – 0.3 µm or better (please see Table 1).

Note: On request, OD can be supplied only on agreed positive tolerances suitable for future machining (for example for telescopic cylinders). For such purpose the tubes can be pre-machined using a center-less grinding process, the final OD value and OD variation being necessary to be agreed.


 - Max 0.5 mm/1000 mm

 - Total deviation for tubes with length 6 m: max. 3.5 mm/length.

 - Total deviation for tubes with length > 6 m: for each meter over 6 m the tolerance must be increased by 0.5 mm.

Roundness and eccentricity

-   OD and ID roundness deviation shall be within the limits of the OD and ID tolerances.

 - Eccentricity shall be maximum 5%.

 - Eccentricity calculated by formula: 


Where Wt max, Wt min are maximum and minimum measured wall thickness in same cross-section.

 Chemical composition (%) 
 Mechanical properties 
 Impact test 
 Non-destructive testing 
 Tube ends preparation

 - Square cut to the longitudinal axis of the tubes with a slight bevel on outside surface.

 - Protected with plastic caps.


-  Minimum and maximum manufacturing lengths according to Table 1. Usually, the tubes shall be supplied in random lengths within 2 m variation.

 - As an option fix lengths  or multiple of fix length are available with cutting tolerance of -0/100 mm as well as cut to length pieces in range 0.4 - 4 m, cutting tolerance of -0/+3 mm.

 Surface protection Inside and outside surface oiled by immersion in corrosion preventive oil in order to ensure temporary protection against corrosion during about 6 months storage in covered area, out of excessive humidity and/or direct water contact.
 Marking Continuous marking along the length of the tube with following information: manufacturer’s logo, dimension (OD x ID), steel grade, heat number and the number of standard or other data as per the customers’ request.
 Packaging  Packed in bundles with circular or hexagonal cross-section, bundle weight of maximum 2000 kilograms.
The bundles are tied with protected metallic straps to provide protection against mechanical damage and corrosion during storage and in transit.
 Mill test report  Mill test reports are issued to customer requirements. Usually it comply with EN 10204 – 3.1