PRECISION COLD DRAW TUBES
STATE OF SUPPLY
Cold drawn/hard
DIN EN 10305 DIN 2391
+ C BK
No heat treatment after the final cold drawing. Therefore, the tube has low strain capacity and mechanical stress as a function of mechanical stress.
Cold drawn/soft
DIN EN 10305 DIN 2391
+ LC BKW
Final heat treatment is followed by a suitable drawing pass (limited reduction of area).For this condition the tube allows within certain limits deformation operations (enlargement, bending, kneading, etc.)
Cold drawn and stress relieved
DIN EN 10305 DIN 2391
+ SR BKS
After final cold drawing the tubes are stress relieved in a controlled atmosphere.
Annealed + A
DIN EN 10305 DIN 2391
+ A GBK
After the final drawing pass the tube is subjected to an annealing heat treatment at a temperature below the critical zone (920 °C).
Normalized
DIN EN 10305 DIN 2391
+ N NBK
After the final drawing pass the tube is subjected to a heat treatment in a controlled atmosphere furnace, temperature above the critical zone (920° C)
APPLICATION
Cold shaped tubes (drawing), with high dimensional accuracy, surface quality and well defined mechanical properties.
Widely used in the industries of auto parts, bearings, systems and hydraulic connections, refrigeration, mechanical industry, ore drilling, industrial chains, hydraulic cylinders, etc.
CHEMICAL COMPOSITION
DIN EN 10305-1:2016-08
Grade | Grade | C | Si | Mn | P | S |
---|---|---|---|---|---|---|
E235 | 1.0308 | ≤ 0,17 | ≤ 0,35 | ≤ 1,20 | ≤ 0,025 | ≤ 0,025 |
E355 | 1.0580 | ≤ 0,22 | ≤ 0,55 | ≤ 1,60 | ≤ 0,025 | ≤ 0,025 |
DIN 2391-2:1994-09
Grade | Grade | C | Si | Mn | P | S |
---|---|---|---|---|---|---|
St 35 | 1.0308 | ≤ 0,17 | ≤ 0,35 | ≥ 0,40 | ≤ 0,025 | ≤ 0,025 |
St 52 | 1.0580 | ≤ 0,22 | ≤ 0,55 | ≤ 1,60 | ≤ 0,025 | ≤ 0,025 |
MECHANICAL PROPERTIES
(minimum values)
DIN EN 10305-1:2016-08
+ C | + LC | + SR | + A | + N | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Grade | Steel Number | Rm MPa | AL [%] | Rm MPa | AL [%] | Rm MPa | ReH MPa | AL [%] | ReH MPa | AL [%] | Rm MPa | ReH MPa | AL [%] |
E235 | 1.0308 | 480 | 6 | 420 | 10 | 420 | 350 | 16 | 315 | 25 | 340 – 480 | 235 | 25 |
E355 | 1.0580 | 640 | 4 | 580 | 7 | 580 | 450 | 10 | 450 | 22 | 490 – 630 | 355 | 22 |
DIN 2391-2:1994-09
BK | BKW | BKS | GBK | NBK | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Grade | Steel Number | Rm MPa | AL [%] | Rm MPa | AL [%] | Rm MPa | ReH MPa | AL [%] | ReH MPa | AL [%] | Rm MPa | ReH MPa | AL [%] |
E235 | 1.0308 | 480 | 6 | 420 | 10 | 420 | 315 | 14 | 315 | 25 | 340 – 470 | 235 | 25 |
E355 | 1.0580 | 640 | 4 | 580 | 7 | 580 | 420 | 10 | 490 | 22 | 490 – 630 | 355 | 22 |
Rm MPa = tensile strength | AL% = elongation | ReH Mpa = yield strength