Tianjin Brisk Metalwork Co., Ltd. is one of the leading manufacturers and suppliers of carbon steel hollow sections in China. We have world-leading production equipment and strong manufacturing capabilities. Please feel free to buy bulk durable carbon steel hollow sections from our factory.
Which Carbon Steel Grades Do We Supply?
Grades are named differently in each standard system, but they answer the same question: how much load can this tube carry, and how does it behave in cold weather or under impact?
European grades (EN 10210 and EN 10219)
| Grade | Minimum yield strength | Tensile strength | Impact test |
|---|---|---|---|
| S235JRH | 235 MPa | 360 - 510 MPa | 27 J at +20 C |
| S275J0H | 275 MPa | 410 - 560 MPa | 27 J at 0 C |
| S275J2H | 275 MPa | 410 - 560 MPa | 27 J at -20 C |
| S355J0H | 355 MPa | 470 - 630 MPa | 27 J at 0 C |
| S355J2H | 355 MPa | 470 - 630 MPa | 27 J at -20 C |
Values are the usual minimums for thinner walls; strength figures reduce slightly as thickness increases, so please check the standard for your wall.
How to read the name: "S" means structural steel, the number is the minimum yield in MPa, "J" refers to the impact energy level (27 J), "0" or "2" show the test temperature (0 C or -20 C), and "H" marks a hollow section.
North American, Australian and Japanese grades
| Standard | Common grades | Approximate minimum yield |
|---|---|---|
| ASTM A500 | Grade B, Grade C | About 290 - 320 MPa (B), 315 - 345 MPa (C), depending on shape |
| ASTM A1085 | Grade A | 345 MPa, with impact requirements |
| ASTM A501 | Grade A, Grade B | About 250 MPa (A), 345 MPa (B) |
| AS/NZS 1163 | C250, C350, C450 | 250 / 350 / 450 MPa |
| JIS G 3466 | STKR400, STKR490 | About 245 / 325 MPa |
Treat these as guide values. Always confirm minimum yield, tensile strength and elongation against the current edition of your project's standard.
How Do Chemical Composition and Weldability Connect?
A tube is only useful if it can be welded on site without cracking. Weldability depends on carbon equivalent (CEV), a figure calculated from carbon, manganese, chromium, molybdenum, vanadium, nickel and copper.
- Lower CEV means easier welding with lower preheat risk, which suits site work and thick walls.
- Higher strength grades such as S355 carry slightly more manganese, so welding procedure and consumables deserve attention on heavy walls.
- Phosphorus and sulphur are held low, because they increase brittleness and reduce toughness.
When you order, tell us whether the tube will be welded in a shop or on site, and the wall thickness at the joint. We can then confirm the grade and the testing that suits your welding procedure.
Which Hollow Section Type Matches Which Grade?
The manufacturing route changes how the same carbon steel behaves. Our related product pages:
- Cold Formed Structural Steel Tube: EN 10219 and ASTM A500 sections with tight dimensional control, ideal for most building frames.
- Hot Finished Structural Steel Tube: EN 10210 sections with uniform properties around the section, preferred for heavy walls and demanding loads.
- Hot Formed Structural Hollow Section: hot processed sections for structures where consistent properties matter.
- Welded Hollow Structural Sections and Electric Resistance Welded Hollow Section: economical carbon steel tube across a wide size range.
- Precision Structural Hollow Section: tighter size and straightness for machine frames and exposed work.
- Heavy Duty Structural Hollow Section: thick-wall carbon steel members for high loads.
For broader coverage of the full range, see our guide to structural steel hollow sections on this site.
Do Carbon Steel Pipes and Hollow Sections Share the Same Materials?
Yes, in many cases the same steel family is used, but the product standard changes. If your project mixes structural tube and pressure or line pipe, these pages help you separate them:
| Product | Standard | Typical grade | Page |
|---|---|---|---|
| Structural tube | EN 10210 / EN 10219 | S355J2H | EN 10210, EN 10219 |
| General purpose pipe | ASTM A53 | Grade B | ASTM A53 |
| High-temperature seamless pipe | ASTM A106 | Grade B | ASTM A106 |
| Line pipe | API 5L | Grade B and higher | API 5L |
| General steel | JIS G 3101 | SS400 | JIS G 3101 |
| Low-pressure welded steel pipe | EN 10217-1 | P235TR1 and similar | EN 10217-1 |
For seamless carbon steel options, see Carbon Steel Seamless Pipe and ASTM A106 Seamless Steel Pipe. Large-diameter welded options are covered under LSAW pipe.
Does a Higher Grade Always Mean a Better Choice?
Not always. This is the most common over-specification we see.
- Strength increases with grade, stiffness does not. All carbon steels share nearly the same modulus of elasticity, so a member governed by deflection or buckling gains little from moving from S235 to S355.
- Higher grades cost more per tonne and may need stricter welding control.
- Lower grades are fine for secondary members, light frames and non-critical supports.
The right grade is the lowest one that meets the design check, with impact grade chosen for the lowest service temperature. If you are not sure, send us the member loads or the design standard and we will help narrow the choice.
Which Finish Protects Carbon Steel in Service?
Carbon steel rusts when exposed to moisture, so the finish matters as much as the grade:
- Black Structural Hollow Section: mill finish for members that will be painted, galvanized or enclosed.
- Galvanized Structural Hollow Section: zinc protection inside and out for outdoor and exposed structures.
- Painted and coated sections: primer or paint systems for indoor frames and members that receive a topcoat.
FAQ
Q: What is the difference between S235, S275 and S355?
A: The number is the minimum yield strength in MPa. S355 carries about 50% more yield strength than S235, so it suits heavier loads or lighter members.
Q: What does the J0 or J2 in S355J0H or S355J2H mean?
A: It marks the impact test temperature: 27 J at 0 C for J0 and at -20 C for J2. Choose by the lowest service temperature of the structure.
Q: Is ASTM A500 Grade C equivalent to S355?
A: They are close in yield strength but not identical, and the standards differ in tolerances and testing. Equivalence needs the designer's approval.
Q: Can carbon steel hollow sections be galvanized?
A: Yes. Grade and wall thickness affect the zinc coating, so tell us the finish before ordering.
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