Seamless Steel Tubes for Structural Purposes GB/T 8162
We are manufacturer of Seamless Steel Tubes in China, if you want to buy Seamless Carbon Steel Tube, Oil Cylinder Steel Tube, Precision Seamless Steel Tube, Hydraulic Cylinder Steel Tube, please contact us.
Our main products:Seamless Steel Tubes,Seamless Carbon Steel Tube,Oil Cylinder Steel Tube,Precision Seamless Steel Tube,Hydraulic Cylinder Steel Tube
Spec:
Material:10# 20# 45# Q235 Q395 Q345
Size Range:OD:4-1200mm
WT:0.3-200mm
General Length:1-12.5m
Tolerance:
According to the following tables or customers` request.
Tolerance of the OD &WT:
OD Tolerance:
| Production Method | OD Tolerance |
| Hot Rolling(Extrusion) | ±1% or ±0.50mm |
| Cold Drawn(Cold Rolled) | ±1% or ±0.30mm |
Tolerance for wall thickness:
1.Wall thickness tolerance of Hot Rolling steel tube:
| Production Method | OD (DN) | WT/OD | Tolerance |
| Extruded tube | ≤102 | / | ±12.5% or ±0.40mm |
| ＞102 | ≤0.05 | ±15% or ±0.40mm |
| ＞0.05-0.10 | ±12.5% or ±0.40mm |
| ＞0.10 | +12.5% -10% |
| Heat expanding steel tube | / | ±15% |
2.Wall thickness tolerance of Cold Drawn(Cold Rolled) steel tube:
| Production Method | WT | Tolerance |
| Cold Drawn(Cold Rolled) steel tube | ≤3 | +15%/-10% or ±0.40mm |
| ＞3 | +12.5% -10% |
Bending tolerance:
WT≤15mm, Bending≤1.5mm/m
WT＞15mm~30mm, Bending≤2.0mm/m
WT＞30mm/OD≥351mm, Bending≤3.0mm/m
Ovality and Wall unevenness:
The ovality and wall unevenness should be no more than 80% of the OD and wall thickness.(Or according to customer`s request)
mechanical property
| Steel Grade | Tensile strength Rm N/mm2(MPa) | Yield Strength Rp0.2 N/mm2(MPa) | Elongation A % |
| Wall Thickness |
| ≤16mm | ＞16~30mm | ＞30mm |
| 10 | ≥335 | ≥205 | ≥195 | ≥185 | ≥24 |
| 15 | ≥375 | ≥225 | ≥215 | ≥205 | ≥22 |
| 20 | ≥410 | ≥245 | ≥235 | ≥225 | ≥20 |
| 25 | ≥450 | ≥275 | ≥265 | ≥255 | ≥18 |
| 35 | ≥510 | ≥305 | ≥295 | ≥285 | ≥17 |
| 45 | ≥590 | ≥335 | ≥325 | ≥315 | ≥14 |
| 20Mn | ≥450 | ≥275 | ≥265 | ≥255 | ≥20 |
| 25Mn | ≥490 | ≥295 | ≥285 | ≥275 | ≥18 |
| Q235 | A | 375~500 | ≥235 | ≥225 | ≥215 | ≥25 |
| B |
| C |
| D |
| Q275 | A | 415~540 | ≥275 | ≥265 | ≥255 | ≥22 |
| B |
| C |
| D |
| Q295 | A | 390~570 | ≥295 | ≥275 | ≥255 | ≥22 |
| B |
| Q345 | A | 470~630 | ≥345 | ≥325 | ≥295 | ≥20 |
| B |
| C | ≥21 |
| D |
| E |
| Q390 | A | 490~650 | ≥390 | ≥370 | ≥350 | ≥18 |
| B |
| C | ≥19 |
| D |
| E |
| Q420 | A | 520~680 | ≥420 | ≥400 | ≥380 | ≥18 |
| B |
| C | ≥19 |
| D |
| E |
| Q460 | C | 550~720 | ≥460 | ≥440 | ≥420 | ≥17 |
| D |
| E |
Test:
- Bending test
- Hardness test
- Impact test
- Squeezing test
- Non-destructive test
Characteristic:
TORICH QUALITY ASSURANCE
Good Surface Quality
Good OD and ID tolerance controlled to Technical Standard
Stable quality
100% Eddy Current Test
Processing:hot rolling(extrude expand), cold drawn(rolling)
RAW MATERIAL
↓
INCOMING INSPECTION
↓
STORAGE → CUTTING→HAMMERING → PICKING LUBRICATION → CLEANING → PHOSPHORI CLEAN
↓
ENDS CUTTING←STRAIGHTENING←HEAT TREATMENT↔MIDDLLE CHECK↔ COLD DRAWING ← LUBRICATING
↓
FINAL INSPECTION→BUNDING→STORAGE
Technical Delivery Conditions:hot rolling, annealing, normalizing
Widely used in the field of:Transporting water,gas,oil etc
Product Images:
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