The advantage of steel tubes for precision applications is the high precision of their manufacturing, the good quality of their surface, and the guaranteed mechanical and technological properties. That is why the pipes are widely used in the machining industry and in the automotive industry. Welded pipes for precision applications are manufactured in the process of cold drawing.
Delivery condition
Designation | Symbol | Description |
Cold drawn / hard | +C | Without thermal processing, after the process of cold drawing is finished |
Cold drawn / soft | +LC | After final thermal processing, appropriate drawing |
Cold drawn and annealed | +SR | After the final cold drawing process and annealing thermal processing in a controlled atmosphere |
Annealed | +A | After the final cold drawing process, the pipes are annealed in a controlled atmosphere |
Normalized | +N | After the final cold drawing process, the pipes are normalized in a controlled atmosphere |
Mechanical properties in room temperature
Steel grade | Maximum values depending on the delivery condition | |||||||||||
+C | +LC | +SR | +A | +N | ||||||||
Steel symbol | Rm MPa | A % | Rm MPa | A % | Rm MPa | ReH Mpa | A % | Rm MPa | A % | Rm MPa | ReH Mpa | A % |
E155 | 400 | 6 | 350 | 10 | 350 | 245 | 18 | 260 | 28 | 270 do 410 | 155 | 28 |
E195 | 420 | 6 | 370 | 10 | 370 | 260 | 18 | 290 | 28 | 300 do 440 | 195 | 28 |
E235 | 490 | 6 | 440 | 10 | 440 | 325 | 14 | 315 | 25 | 340 do 480 | 235 | 25 |
E275 | 560 | 5 | 510 | 8 | 510 | 375 | 12 | 390 | 21 | 510 do 550 | 275 | 21 |
E355 | 640 | 4 | 590 | 6 | 590 | 435 | 10 | 450 | 22 | 490 do 630 | 355 | 22 |
Chemical composition (ladle analysis)
Steel grade | % of the mass | ||||
Steel symbol | C max | Si max | Mn max | P max | S max |
E155 | 0,11 | 0,35 | 0,70 | 0,025 | 0,025 |
E195 | 0,15 | 0,35 | 0,70 | 0,025 | 0,025 |
E235 | 0,17 | 0,35 | 1,20 | 0,025 | 0,025 |
E275 | 0,21 | 0,35 | 1,40 | 0,025 | 0,025 |
E355 | 0,22 | 0,35 | 1,60 | 0,025 | 0,025 |
Inspection and test list
Inspection or test type | Test frequency | ||
Internal tests | Acceptance test | ||
Mandatory | Chemical analysis | M | M |
Tensile testing | M | One per tested batch | |
Dimension verification | M | M | |
Visual inspection | M | M | |
Optional | Flattening test or expansion test (option 18) | M | One per tested batch |
Roughness testing | Not applicable | One per tested batch | |
NDT of the weld in order to identify any longitudinal discontinuities | Not applicable | Individual | |
NDT in order to detect any leaks |