Seamless pipes
PN-EN 10305-1 ||| Steel tubes for precision applications – cold drawn
PN-EN 10305-1 Steel tubes for precision applications – cold drawn
The advantage of steel tubes designed for precision applications is their high precision with which they are manufactured, the good quality of their surface, a wide selection of dimensions and guaranteed mechanical and technological properties. It is for those reasons that the pipes are widely used in the mechanical engineering industry and in the automotive industry. Pipes for precision applications are manufactured as cold drawn pipes.
The pipes are manufactured with the diameters between 4 – 120 mm and with the wall thickness of up to 12,5 mm.
The pipes are manufactured without thermal processing or with thermal processing: normalization or annealing.
| PN-EN 10305-1 | PN-EN 10297-1 | DIN 2391 | |
| Standard description | Seamless cold drawn steel tubes. | Seamless circular steel tubes for mechanical and general engineering purposes. Non-alloy and alloy steel tubes. | Seamless precision steel tubes |
PN-EN10305-1
| Pipe types | Steel grades | Resistance properties | |||||||||||
| +C | +LC | +SR | +A | +N | |||||||||
| Rm [MPa] | A% | Rm [MPa] | A% | Rm [MPa] | Re [MPa] | A% | Rm [MPa] | A% | Rm [MPa] | Re [MPa] | A% | ||
| Precision E235, E255, E355 According to PN-EN 10305-1 |
E235 | 480 | 6 | 420 | 10 | 420 | 350 | 16 | 315 | 25 | 340- 480 | 235 | 25 |
| E255 | 580 | 5 | 520 | 8 | 520 | 375 | 12 | 390 | 21 | 440- 570 | 255 | 21 | |
| E355 | 640 | 4 | 580 | 7 | 580 | 450 | 10 | 450 | 22 | 490- 630 | 355 | 22 | |
| C34E | 590 | 5 | 540 | 7 | - | - | - | 440 | 22 | >\= 460 | 280 | 21 | |
| C45E | 720 | 4 | 670 | 6 | - | - | - | 510 | 20 | >\= 540 | 340 | 18 | |
| Pipe types | CHEMICAL COMPOSITION (LADLE ANALYSIS) | ||||||||||
| C% | Si% | Mn% | P% | S% | Cr% | Mo% | V% | Inne% | Cr+ Mo+ Ni Max% | Al.% | |
| E235 | <\=0,17 | <\=0,35 | <\=1,20 | <\=0,025 | <\=0,025 | - | - | - | - | - | 0,020- 0,060 |
| E255 | <\=0,21 | <\=0,35 | 0,40-1,10 | <\=0,025 | <\=0,025 | - | - | - | - | - | 0,020- 0,060 |
| E355 | <\=0,22 | <\=0,55 | <\=1,60 | <\=0,025 | <\=0,025 | - | - | - | - | - | 0,020- 0,060 |
| C35E | 0,32-0,39 | <\=0,40 | 0,50-0,80 | 0,035 | <\=0,035 | <\=0,40 | <\=0,10 | - | - | 0,63 | - |
| C45E | 0,42-0,55 | <\=0,40 | 0,50-0,80 | 0,035 | <\=0,035 | <\=0,40 | <\=0,10 | - | - | 0,63 | - |
Depending on the state of cold processing in the finishing pass, the yield limit can be close to the tensile strength limit. In order to calculate the value, it is recommended to apply the following dependencies:
- for the delivery condition + C: ReH >\=0,8Rm
- for the delivery condition + LC ReH >\=0,7Rm
In order to calculate the value, it is recommended to apply the following dependency ReH>\=0,5Rm
For pipes with the outside diameter of </=30mm and the wall thickness of <\=3mm, the minimum values of ReH are 10MPa lower than the values provided in the table.
For pipes with the outside diameter of >160mm: ReH >\=420MPa.
Inspection and test list for the EN 10305-1:2002 standard
| 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 20) | M | One per tested batch |
| Roughness measurement | Not applicable | One per tested batch | |
| NDT in order to identify longitudinal discontinuity | Not applicable | Individual | |
| NDT in order to identify leaks | |||
Inspection and test list for the EN 10305-4:2003 standard
| Inspection or test types | Test frequency | |
| Internal test | Acceptance test | |
| Chemical analysis | M | M |
| Tensile testing | M | One per tested batch |
| Flattening test or extension test | M | Two per tested batch |
| Dimension verification | M | M |
| Visual inspection | M | M |
| NDT in order to identify leaks | Individual | Individual |
PN-EN 10297-1
Tubes for mechanical purposes, hot rolled and cold drawn. .
| Minimum mechanical properties | ||||||||||||
| Pipe type | Steel grades | Delivery condition | Upper yield limit Re MPa | Tensile strength Rm MPa | Elongation A% |
|||||||
| Seamless circular steel tubes for mechanical and general engineering purposes E235, E275, E355, According to PN-EN 10297-1 | For T in mm | For T in mm | 1 | t | ||||||||
| <\= 16 | >16 <\=40 | >40 <\=65 | >65 <\=80 | >80 <\=100 | <\=16 | >16 <\=40 | >40 <\=65 | |||||
| E235 | +A lub+N | 235 | 215 | 205 | 195 | 360 | 360 | 360 | 340 | 340 | 25 | |
| E275 | +A lub+N | 275 | 255 | 245 | 235 | 410 | 410 | 410 | 380 | 380 | 22 | |
| E355 | +A lub+N | 354 | 345 | 315 | 295 | 490 | 490 | 410 | 470 | 470 | 20 | |
| Minimum mechanical properties | ||||||||||||
| Pipe type | Steel grades | Upper yield limit Re MPa |
Tensile strength Rm MPa | Elongation A% | ||||||||
| Seamless circular steel tubes for mechanical and general engineering purposes E235, E275, E355, According to PN-EN 10297-1 | For T in mm | For T in mm | For T in mm | |||||||||
| <\=16 | >16 <\=40 | >40 <\=80 | <\=16 | >16 <\=40 | >40 <\=80 | <\=16 | >16<\=40 | >40<\=80 | ||||
| 1 | t | 1 | t | 1 | ||||||||
| C35E | 300 | 270 | 270 | 550 | 520 | 520 | 18 | 16 | 19 | 17 | 19 | |
| C45E | 340 | 305 | 305 | 620 | 580 | 580 | 14 | 12 | 16 | 14 | 16 | |
| Steel grades | CHEMICAL COMPOSITION (LADLE ANALYSIS) | |||||||
| C% | Si% | Mn% max | P% | S% | ||||
| min | max | min | max | min | max | max | Max | |
| E235 | - | 0,17 | - | 0,35 | - | 1,20 | 0,030 | 0,035 |
| E275 | - | 0,21 | - | 0,35 | - | 1,20 | 0,030 | 0,035 |
| E355 | - | 0,22 | - | 0,55 | - | 1,60 | 0,030 | 0,035 |
| C35E | 0,32 | 0,39 | - | 0,40 | 0,50 | 0,80 | 0,035 | 0,035 |
| C45E | 0,42 | 0,50 | - | 0,40 | 0,50 | 0,80 | 0,035 | 0,035 |
Inspection and test list for the EN 10297-1:2003 standard
| Inspection and test type | Internal inspection and testing | Acceptance inspection and testing | |
| Mandatory tests | Ladle analysis | According to the manufacturer’s procedures | 1/per ladle |
| Tensile testing | According to the manufacturer’s procedures | 1/per tested batch | |
| Resilience testing | Not applicable | 1 set/ per tested batch | |
| Dimension verification | - | ||
| Visual inspection | |||
| Material identification for alloy steel tubes | Not applicable | Individual | |
| Additional tests | Tensile testing on samples after thermal processing | Not applicable | 1/ per ladle |
| Tensile testing | Not applicable | 1/ per tested batch | |
| Resilience testing | Not applicable | 1 set/ per tested batch | |
| Hardness range verification | Not applicable | According to a documented procedure | |
| Hardness testing | Not applicable | 1/ per tested batch | |
| Temper testing | Not applicable | 1/ per ladle | |
| Non-destructive testing in order to identify any discontinuities | Not applicable | Individual | |
| Tightness testing | Not applicable | Individual | |
DIN 2391
Seamless precision steel tubes
Grades: St35, St45, St52
| Pipe types | Steel grades | Minimum resistance properties | |||||||||||
| +C | +LC | +SR | +A | +N | |||||||||
| Rm [MPa] | A% | Rm [MPa] | A% | Rm [MPa] | Re [MPa] | A% | Rm [MPa] | A% | Rm [MPa] | Re [MPa] | A% | ||
| Precise seamless steel pipes St35, St45, St52 According to DIN 2391 | St 35 | 480 | 6 | 420 | 10 | 420 | 350 | 14 | 315 | 25 | 340- 470 | 235 | 25 |
| St 45 | 580 | 5 | 520 | 8 | 520 | 375 | 12 | 390 | 21 | 440- 570 | 255 | 21 | |
| St 52 | 640 | 4 | 580 | 7 | 580 | 420 | 10 | 490 | 22 | 490- 630 | 355 | 22 | |
The yield limit for the annealed delivery condition (GBK) is at least 50% of the tensile strength value. Depending on the level of deformation, the yield limit can be higher in the case of pipes in the cold-finished - hard (BK) and cold-finished – soft (BKW) delivery conditions and amount to a value that is close to the tensile strength value. In order to calculate the yield limit, it is recommended to apply the following values: delivery condition
Drawn b.t >\=80% of tensile strength
Drawn b.m >\=70% of tensile strength
In the case of pipes with the outside diameter <\= 30mm whose wall thickness is <\=3mm, the yield limit value is lower by 10N/mm2
| Steel grades | CHEMICAL COMPOSITION (LADLE ANALYSIS) | ||||
| AC% | Si% | Mn% | P% | S% | |
| St35 | </=0,17 | <\=0,35 | >\=0,40 | <\=0,025 | <\=0,025 |
| St45 | <\=0,21 | <\=0,35 | >\=0,40 | <\=0,025 | <\=0,025 |
| St52 | <\=0,22 | <\=0,55 | >\=1,60 | <\=0,025 | <\=0,025 |
The permissible addition of microscopic elements is as follows:
Nb<\=0,03%; Ti<\=0,03%; v<\=0,05%; NB + Ti + V <\=0,05%
A review of the test scope for pipes with acceptance testing certificatese
| Tests | Test scope |
Person responsible for test execution | |
| No | Type | ||
| 1 | Tensile testing | 1 test pipe for every batch 1 sample | As agreed |
| 2 | Flattening test | At one of the test pipe ends according to no 1, 1 sample | As agreed |
| 3 | Expansion testing | At one of the test pipe ends according to no 1, 1 sample | As agreed |
| 4 | Roughness verification | If agreed: test pipe according to no 1, 1 sample | Manufacturer |
| 5 | Dimension verification | All pipes | As agreed |
| 6 | Surface inspection | All pipes | As agreed |
| 7 | Tightness testing | If agreed: all pipes | Manufacturer |
| 8 | Non-destructive testing | If agreed: all pipes | Manufacturer |
