Round Cold Drawn Seamless Hydraulic Steel Tube 

1. Description

Cold Finished Seamless Hydraulic Steel tube is a drawn tube which has been normalised (heat treated) to give it good flexibility. It is popular in hydraulic applications such as oil and water conveying and pneumatic applications. Cold Drawn 

Seamless Hydraulic steel tube and pipe is not suitable for load bearing applications.

Our Cold Drawn Seamless Hydraulic steel tube and pipe is supplied in full compliance with the Standard DIN2391/C EN 10305-4. Typical lengths available are 3 metre and 6 metre, but should you need a different size please let us know when place orders.

2. Specification of  Round Cold Drawn Seamless Hydraulic Steel Tube

2.1 Dimensions

Tubes shall be ordered:

2.1.1. by outside diameter and inside diameter

2.1.2. by outside diameter and wall thickness

2.2 Tolerances

2.2.1. Values according to standards

2.2.2. Tolerances by agreement

2.2.3. Dimensions and tolerances according to standard ASTM A450

2.3 Steel grades

Steel is produced in electric arc furnace and is fully killed. 

2.4 Delivery conditions and heat treatment

BK (+C) Cold finished/hard (cold finished as drawn). No heat treatment after the last cold forming process

BKW (+LC) Cold finished/soft (lightly cold worked). After the last heat treatment there is a light finishing pass (cold drawing).

BKS (+SR) Cold finished/stress relieve annealed. After the final cold forming process the tubes are stress relieve annealed.

GBK (+A) Annealed. After the final cold forming process the tubes are annealed in a controlled atmosphere.

NBK (+N) Normalized. After the final cold forming process the tubes are annealed above the upper transformation point in a controlled atmosphere

2.5 Surface condition

Tube surface corresponds to the standards and depends on the method of tube manufacturing and method of heat treatment. Value of roughness Ra <0.8 µm.

2.6 Tube ends

The tubes are delivered with plain ends without burrs at the ends of the tube.

Upon request ends could be plugged with plastic caps

3.Testing of  Round Cold Drawn Seamless Hydraulic Steel Tube

Testing is performed in accordance with corresponding standards or by agreement

• flattening test , drift expanding test, flaring test, bending test

• mechanical properties test 

• NDT for detection of transverse imperfections and wall imperfections

4. Packing and Protective coating

4.1 Tubes are supplied either uncoated or with the manufacturers standard mill coating at the option of the customer (subject of agreement between customer and manufacturer).