Seamless carbon steel pipe is a hollow tube made by rolling a solid steel billet through a piercing bar. It has no welds throughout, resulting in high strength and pressure resistance, making it suitable for high-pressure pipeline applications, such as pipelines transporting gases or liquids.
Glory Steel is a professional manufacturer and factory of seamless carbon steel pipes. We produce seamless pipes of various diameters, wall thicknesses, and lengths, and offer customization services.
Specification
| Item | Seamless Carbon Steel Pipe |
| Origin | Tianjin, China |
| Material | Q235, Q345, Q345B, Q345D, 20#, 45#, 16Mn, 17Mn, 42CrMo, St37, St52, etc. |
| Standard | ASTM, API, GB/T, DIN, JIS |
| OD | 10 mm – 1000 mm |
| WT | 1.0 mm – 60 mm |
| Length | 1 m – 12 m, customizable |
| Common Sizes | 6 m, 12 m, 6.4 m |
| MOQ | 10 tons |
| Delivery Time | 7 – 14 days |
| Certifications | ISO 9001, API 5L, ASME, CE, PED, SGS |
Production Video
Process and Surface Treatment
| Item | Description |
| Production Process | Hot-rolled / Cold-drawn / Cold-rolled |
| Surface Treatment | Glossy black / Hot-rolled / 3LPE / FBE / Galvanized / Painted |
| Oil Treatment | Non-oiling/rust-preventive oil |
| Pipe End Protection | Plastic tube cap sealing |
| Processing Services | Cutting, cold bending/hot bending, punching/drilling, welding, peeling/straightening |
Material Grades & Chemical Composition
| Standard System | Grade | C (%) | Mn (%) | Tensile Strength | Yield Strength | Applicable Temperature |
| ASTM/ASME | A106 Gr.B | ≤0.30 | 0.29-1.06 | ≥415 | ≥240 | -28~400℃ |
| ASTM/ASME | A53 Gr.B | ≤0.30 | ≤1.20 | ≥415 | ≥240 | ≤400℃ |
| API 5L PSL1/PSL2 | X42-X80 | ≤0.28 | ≤1.40 | 415-690 | 290-555 | -40~600℃ |
| GB/T | 20# | 0.17-0.24 | 0.35-0.65 | ≥410 | ≥245 | -20~425℃ |
| EN | S355J2H | ≤0.22 | ≤1.60 | 510-680 | ≥355 | -20℃ |
Note: Sulfur (S) and phosphorus (P) contents are strictly controlled below 0.035% (API 5L PSL2: ≤0.015%) to ensure corrosion resistance and toughness.
Key Advantages
Process Types of Seamless Steel Pipes
Seamless carbon steel pipes are classified into two main categories according to their manufacturing process: hot-rolled (HRS) and cold-rolled (including cold-drawn, CRS/CDS), and have three forming methods: hot-rolled, cold-rolled, and cold-drawn.
Hot Rolled Seamless Pipe, HRS
- Process: Heating solid steel billet – piercing mill – rolling mill – sizing mill, all at high temperatures.
- Common Standards: ASTM A106 Gr.B, API 5L X42-X80, GB/T 8163 20#
- Features: Wide diameter range, relatively thicker walls. The tube surface has iron oxide scale, making it relatively rough. Low cost. Industrial applications account for over 70%.
Cold Rolled/ Drawn Seamless Pipe, CRS/CDS
- Process: Using hot-rolled tubes as raw material – cold rolling mill (rolling) or cold drawing mill (drawing) – annealing, pickling.
- Cold rolling (CRS): Formed by rolling with rollers, resulting in better wall thickness uniformity.
- Cold drawing (CDS): Formed by drawing with dies, resulting in smaller diameters and longer lengths, suitable for small-diameter precision tubes.
- Common standards: ASTM A179, GB/T 3639, EN 10305-1.
- Features: Relatively smaller diameter, thinner walls, and the main process for precision tubes. Smooth and clean surface, extremely high dimensional accuracy, higher strength and hardness. High cost.
Parameter Comparison Table
| Process | HRS | CRS | CDS |
| Temperature | High Temperature1200℃+ | Room Temperature | Room Temperature |
| Diameter | DN15-DN1200 | DN6-DN100 | DN6-DN50 |
| Wall Thickness | 10mm-150mm | 1mm-20mm | 1mm-10mm |
| Precision | Lower | High | Extremely high |
| Tolerance | ±1.5% | ±0.5% | ±0.1mm |
Application Areas
Mainly used for fluid pipes, boiler pipes, structural pipes, oil well pipes/drill pipes, hydraulic cylinder pipes, fertilizer equipment pipes, API pipes, EMT pipes, and thick-walled pipes. For example, seamless black carbon steel pipe and A106 seamless carbon steel pipe are commonly used engineering pipes.
Application of Hot-Rolled Seamless Steel Pipes
- Power Energy: Superheaters, headers, main steam pipes for thermal/nuclear power boilers; pressurized water pipes for hydroelectric power plants.
- Municipal and Infrastructure: Bridge support columns, building pile foundations, urban water supply networks, sewage treatment.
- Machinery Manufacturing: Large equipment frames, hydraulic cylinder barrels, jack sleeves, heavy machinery components.
- Oil and Gas: Onshore/offshore pipelines, downhole casing/tubing, refinery pipelines.
Applications of CRS/CDS Steel Pipe
- Hydraulics and Pneumatics: Hydraulic hoses for excavators and cranes, high-pressure cylinders, pneumatic components.
- Automotive Industry: Engine oil hoses, drive shafts, shock absorber sleeves, exhaust systems.
- Precision Instruments: Medical equipment conduits, sensor housings, aerospace instrument piping.
- Chemical and Pharmaceutical Industries: Chemical reaction vessel coils, high-purity fluid transport, and laboratory instruments.
Dimension Representation Method
1. Inch System (NPS / Schedule)
- NPS: Nominal Pipe Size, expressed in inches, such as NPS 1/2″, NPS 3/4″, NPS 1″, NPS 2″, etc.
- Schedule (Sch): Wall thickness grade, such as: Sch 40, Sch 80, Sch 160, etc.
2. Metric (mm / DN)
- OD: Outer Diameter, unit mm, e.g., 21.3mm, 26.9mm, 33.7mm, 42.4mm.
- DN: Nominal Diameter, unit mm, e.g., DN15, DN20, DN25, DN32, DN40, etc.
Taking Schedule 40 / Schedule 80 seamless carbon steel pipe as an example, the specification comparison table is as follows.
Common Specifications Comparison Table
| NPS (inched) | DN | OD | Schedule 40 | Schedule 80 |
| 1/2″ | DN15 | 21.3 | 2.8 / 3.0 | 4.5 |
| 3/4″ | DN20 | 26.9 | 2.9 / 3.2 | 4.8 |
| 1″ | DN25 | 33.7 | 3.2 / 3.4 | 4.6 |
| 1¼” | DN32 | 42.4 | 3.5 / 3.6 | 5.0 |
| 1½” | DN40 | 48.3 | 3.7 / 3.7 | 5.2 |
| 2″ | DN50 | 60.3 | 3.9 / 3.9 | 5.5 |
| 2½” | DN65 | 73.0 | 5.2 / 4.0 | 7.0 / 6.0 |
| 3″ | DN80 | 88.9 | 5.5 / 4.5 | 7.6 / 7.6 |
| 4″ | DN100 | 114.3 | 6.0 / 6.0 | 8.6 / 8.6 |
| 6″ | DN150 | 168.3 | 7.1 / 7.1 | 11.0 / 11.0 |
| 8″ | DN200 | 219.1 | 8.2 / 8.2 | 10.3 / 10.3 |
| 10″ | DN250 | 273.0 | 9.3 / 9.3 | 12.7 / 12.7 |
| 12″ | DN300 | 323.9 | 10.3 / 10.3 | 14.3 / 14.3 |
| 16″ | DN400 | 406.4 | 12.7 / 12.7 | 17.5 / 17.5 |
| 20″ | DN500 | 508.0 | 15.1 / 15.1 | 20.6 / 20.6 |
| 24″ | DN600 | 610.0 | 17.5 / 17.5 | 25.4 / 25.4 |
Cooperative Projects
Why Choose Glory Steel?
1. Strict Quality Control: 100% hydrostatic testing and ultrasonic/eddy current testing.
2. High Cost-Effectiveness: Factory direct pricing, eliminating middlemen, with a production capacity of 10,000+ tons/month.
3. Technical Support: Customized solutions based on the temperature, pressure, and corrosion requirements of the operating environment.
4. Fast Delivery: Ample stock of standard materials (such as A106 Gr.B, Q235B, Q345B), supporting priority production for urgent orders. Independent processing and painting workshops allow for non-standard orders to be delivered within 15-20 days.
Get your customized solution and free samples within 10 hours.
Glory Steel Plant, located in Tianjin, China, is an ISO 9001, ISO 14001, and CE certified factory with an annual output of 100,000 tons. We specialize in producing galvanized pipes, stainless steel pipes, and alloy steel pipes. With our high-quality products and services, we export to over 120 countries.
