Precision Seamless tubes are produced using the cold drawn process. Seamless steel tubes can be supplied as cut tubes and bent tubes. Cut tubes are designed especially for manufacturers of automotive components.
Precision steel tubes from our production satisfy the requirements for the following applications: components for the vehicle drivetrain, cars suspension systems, fuel injection, components for engine and transmission, components for body and chassis, vehicle control systems and others.
| Outer Diameter (OD) | Wall Thickness (WT) |
|---|---|
| 4.0 – 125.0 mm | 0.5 – 12.0 mm |
| EN 10305-1 | ASTM 519, SAE1-2 | JIS G3445 | DIN 239 |
|---|---|---|---|
| E215, E235, E255, E355, E410, 26Mn5, 26Mo2, C35E, C45E, 25CrMo4, 42CrMo4, 25CrMo4 | 1008, 1010, 1012, 1015, 1016, 1017, 1018, 1019, 1020, 1021, 1022, 1025, 1026, 1030, 1035, 1040, 1045, 1050, 1518, 4130, 4140, 4142, 8617. | STKM11A, STKM12A, STKM12B, STKM12C, STKM13A, STKM13B, STKM13C, STKM14A, STKM14B, STKM14C, STKM15A, STKM15C, STKM16A, STKM16C, STKM17A, STKM17C, STKM18A, STKM18B, STKM18C, STKM19A, STKM19C, STKM20A | St35, St45, St52. |
| Standard | Grade |
|---|---|
| European Standards | EN 10305-1, DIN 2391, BS 6323/4, NF A 49-310, NF A 49-312, UNI 7945, STN/ČSN 42 6711, STN/ ČSN 42 6712, PN-H 74240, PN-H 74220 |
| Russian Standards | GOST 8734, 9567, 12132 |
| American Standards |
ASTM A450 a A519 |
| Japanese Standards | JIS G3445 |
Tolerances of the precision tubes are in accordance with the appropriate dimensional tables of standards. Usual value for the outside diameter (OD) is less than 0.5% of OD in no heat treatment process used. For the heat treated tubes, tolerance values are depended upon the relation of the wall thickness and the tube diameter (WT/OD) and are larger (up to a single or twofold).
In tolerances of the outside diameter (OD) the allowed deviation of circularity is included. When ordering based on the wall thickness, the tolerance is 10% from the wall thickness. Eccentricity of precision tube is included in the wall thickness tolerance.
Maximum tubes length is 18 meters.
Types of supplied length are:
(a) random length, in the range of 3 – 7 (9) m,
(b) fixed length, ± 500 mm,
(c) exact length, – 0 / + x mm (x upon agreement),
(d) tubes can be supplied as cut tubes
Mandatory testing:
(a) cast / chemical analysis
(b) tensile test,
(c) dimensional inspecti,
(d) visual inspection of the tubes surface.
Optional testing:
(a) flattening test or drift expanding test,
(b) roughness measurement NDT to find longitudinal defects,
(c) eddy current (STN 01 5054, PRP 02-74, SEP 1925, ASTM E 309, EN 10246-3 Gr.E3),
(d) stray flux (STN 01 5047, ČSN 01 5047, SEP 1913, ASTM E 570, EN 10246-5 Gr.F3),
(e) ultrasound (STN 01 5028, ČSN 01 5028, SEP 1915, ASTM E 213, EN 10246-7 Gr.U3),
(f) NDT as a proof of tightness or leakage test by eddy current EN 10246-1.
The tubes with deburred ends or ends customized for welding.
The ends are vertical to the longitudinal axis and are without burrs.
While ordering, it is necessary to agree upon the method and means of temporarily protecting the surface of the tubes during transportation and storiage.
Inspection documents are issued in particular in accordance with EN 10204 or ISO 10474.
EN 10204
2.2 nonspecified testing (only mandatory tests),
3.1 specific testing,
3.2 after agreement.
```Straightness of the tubes is influenced by the mechanical properties of the tubes.
For material having the yield point ReH <= 500 MPa is straightness 0,0015 multiple of the tube length maximum, allowed straightness for one meter length is 1.5 milimeters.
For material with the yield point ReH > 500 MPa the allowable straightness for the whole length of the tube is 0.0020 multiple of the tube length, allowed straightness of one meter is 2 milimeters.
Precision tubes are supplied in condition that is presented in the table below. It is marking for thermal processing according to EN 10305-1.
+C Cold drawn / hard. After the last cold forming no heat treatment.
+LC Cold drawn / soft. After the last heat treatment follows the cold drawing there is a light finishing pass.
+SR Cold drawn and stress relieved annealed. After the final cold drawing process the tubes are stress relieved annealed in a controlled atmosphere.
+A Annealed. After the last cold drawing process the tubes are annealed in a controlled atmosphere.
+N Normalized. After the last cold drawing process the tubes are annealed in a controlled atmosphere.
Marking for material condition according to DIN 2391-2 and ASTM 519.
