Seamless Steel Pipe
Premium seamless carbon, alloy, and stainless steel pipes manufactured from solid billets. No weld seam ensures superior strength for high-pressure and critical applications.
Seamless Steel Pipe
Seamless steel pipes are manufactured from a solid round steel billet which is heated, pierced, and then rolled to form a hollow tube without any welding seam. This manufacturing process ensures superior strength and uniform structure.
CREATEEL supplies premium seamless carbon, alloy, and stainless steel pipes for oil & gas, petrochemical, power generation, and mechanical applications worldwide.
- OD: 1/4″ – 36″ (13.7mm – 914mm)
- Wall Thickness: 1.65mm – 30.96mm (SCH 5S – XXS)
- Length: 3m – 18m, custom lengths available
- Steel Grade: Gr.A/B, 10#/20#, X42–X70, H40–P110
- Standard: API 5L/5CT, ASTM A106/A53, EN 10216, DIN 17175
What is Seamless Steel Pipe?
Seamless steel pipe is a tubular product made without any welded joint or seam. It is produced by piercing a solid billet to create a hollow shell, which is then elongated and reduced to the desired dimensions through hot rolling or cold drawing processes.
Because seamless pipes have no weld seam, they offer superior structural integrity, higher pressure resistance, and better corrosion resistance compared to welded pipes. They are the preferred choice for critical applications in oil & gas, petrochemical, and power generation industries.
Superior structural integrity and pressure capacity
Ideal for high-pressure and high-temperature service
Consistent wall thickness throughout the pipe
Smooth surface finish resists corrosion effectively
Technical Specifications
Seamless Pipe Dimensions (Carbon Steel)
OD Range: 1/4″ – 36″ (13.7mm – 914mm) | Wall Thickness: SCH 5S – XXS | Length: 3m – 18m
| DN (mm) | NPS (in) | OD (mm) | Wall Thickness (mm) |
|---|---|---|---|
| 15 | 1/2 | 21.3 | 1.65–7.47 |
| 20 | 3/4 | 26.7 | 1.65–7.82 |
| 25 | 1 | 33.4 | 1.65–9.09 |
| 32 | 1-1/4 | 42.2 | 1.65–9.70 |
| 40 | 1-1/2 | 48.3 | 1.65–10.15 |
| 50 | 2 | 60.3 | 1.65–11.07 |
| 65 | 2-1/2 | 73.0 | 2.11–14.02 |
| 80 | 3 | 88.9 | 2.11–15.25 |
| 100 | 4 | 114.3 | 2.11–17.12 |
| 125 | 5 | 141.3 | 2.77–19.05 |
| 150 | 6 | 168.3 | 2.77–21.95 |
| 200 | 8 | 219.1 | 2.77–22.23 |
| 250 | 10 | 273.1 | 3.40–25.40 |
| 300 | 12 | 323.9 | 3.40–28.58 |
| 350 | 14 | 355.5 | 3.40–31.75 |
| 400 | 16 | 406.4 | 3.40–36.53 |
| 450 | 18 | 457.2 | 3.40–39.67 |
| 500 | 20 | 508.0 | 3.40–44.45 |
| 600 | 24 | 609.6 | 3.40–52.37 |
Chemical Composition (%)
| Grade | C (max) | Mn | Si | P (max) | S (max) |
|---|---|---|---|---|---|
| ASTM A106 Gr.A | ≤0.25 | ≤0.27–0.93 | ≥0.10 | ≤0.035 | ≤0.035 |
| ASTM A106 Gr.B | ≤0.30 | 0.29–1.06 | ≥0.10 | ≤0.035 | ≤0.035 |
| ASTM A106 Gr.C | ≤0.35 | 0.29–1.06 | ≥0.10 | ≤0.035 | ≤0.035 |
| API 5L Gr.B PSL2 | ≤0.24 | ≤1.20 | ≤0.45 | ≤0.025 | ≤0.015 |
| API 5L X42 | ≤0.22 | ≤1.30 | ≤0.45 | ≤0.025 | ≤0.015 |
| API 5L X52 | ≤0.22 | ≤1.40 | ≤0.45 | ≤0.025 | ≤0.015 |
| API 5L X60 | ≤0.16 | ≤1.60 | ≤0.45 | ≤0.020 | ≤0.010 |
| API 5L X65 | ≤0.16 | ≤1.65 | ≤0.45 | ≤0.020 | ≤0.010 |
| API 5L X70 | ≤0.16 | ≤1.70 | ≤0.45 | ≤0.020 | ≤0.010 |
| 20# (GB/T 699) | 0.17–0.23 | 0.35–0.65 | 0.17–0.37 | ≤0.035 | ≤0.035 |
| 16Mn (Q345) | ≤0.20 | 1.00–1.60 | ≤0.55 | ≤0.030 | ≤0.030 |
Note: Values as per API 5L / ASTM A106 standards. Actual chemistry may vary by heat. Full mill test certificates provided.
Mechanical Properties
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) |
|---|---|---|---|
| ASTM A106 Gr.A | ≥330 | ≥205 | ≥35 |
| ASTM A106 Gr.B | ≥415 | ≥240 | ≥30 |
| ASTM A106 Gr.C | ≥485 | ≥275 | ≥20 |
| API 5L Gr.B PSL2 | 415–760 | 245–450 | ≥24 |
| API 5L X42 | 415–760 | 290–495 | ≥22 |
| API 5L X52 | 415–760 | 360–530 | ≥20 |
| API 5L X60 | 415–760 | 415–565 | ≥18 |
| API 5L X65 | 435–760 | 435–600 | ≥18 |
| API 5L X70 | 435–760 | 485–635 | ≥17 |
| 20# (GB/T 699) | ≥410 | ≥245 | ≥20 |
| 16Mn (Q345) | 470–630 | ≥345 | ≥22 |
Note: Values are minimum unless specified as range. Mechanical properties may vary based on wall thickness and heat treatment.
Seamless Pipe Manufacturing Process
Solid round steel billets sourced from top mills (Baosteel, Shougang) are inspected and cut to specified lengths.
Billets are heated in a rotary hearth furnace to 1200–1280°C for optimal pierceability.
The heated billet is pierced by a cross-roll piercer to form a hollow shell (mother tube).
The hollow shell is elongated and wall-thickness reduced through a mandrel mill or plug mill.
The pipe passes through a sizing mill to achieve precise outside diameter dimensions.
Pipes are cooled on a cooling bed to stabilize the microstructure.
Pipes are straightened using a rotary straightener to meet straightness tolerances.
Pipes are cut to required lengths and subjected to visual and dimensional inspection.
Normalizing, annealing, or quenching & tempering as required by specifications.
Hydrostatic test, ultrasonic test, eddy current test, and mechanical testing.
Beveling, threading, or plain end finishing per customer requirements.
Oiling, varnishing, painting, or coating as per specification requirements.
Available Coating & Packing Options
Black Paint / Varnish
Standard protective coating for general purpose and structural applications.
Hot-Dip Galvanized
Zinc coating (40–120μm) for enhanced corrosion resistance in outdoor environments.
3PE Coating
Three-layer polyethylene coating for buried pipelines and harsh corrosion environments.
FBE Coating
Fusion bonded epoxy for oil & gas pipelines operating at temperatures up to 90°C.
Epoxy Lining
Internal epoxy coating for water supply, fire fighting, and potable water systems.
Oiled / Bare
Light oil coating or bare finish for applications requiring further processing.
📦 Packing Methods
- Bundles with steel wire straps
- Wrapped with waterproof plastic woven bag
- Ends protected by plastic caps
- Bulk in container for large OD pipes
- Crates for small diameter pipes
- Custom packing per buyer requirements
🚢 Shipping Information
- MOQ: 5 tons per size
- Delivery: 7–30 days (stock available)
- Port: Tianjin / Xingang, China
- Container: 20ft / 40ft GP/HQ
- Payment: T/T, L/C, D/P accepted
- Insurance: CIF terms include All Risk
💡 Tip: We provide mill test certificates (MTC) as per EN 10204 3.1/3.2, third-party inspection (SGS, BV, TUV), and full traceability documentation for every order.
Application Areas
🧪 Oil & Gas
Transmission pipelines, downhole tubing, and casing for oil and natural gas exploration and production
🏭 Petrochemical
Process piping, refinery lines, and chemical plant piping systems for corrosive fluid handling
⚡ Power Generation
Boiler tubes, superheater tubes, and high-temperature steam lines in power plants
💧 Water Supply
High-pressure water transmission, fire fighting systems, and potable water distribution
🔧 Mechanical Engineering
Hydraulic cylinders, pneumatic systems, and precision machinery components
🏗 Construction
Structural supports, piling foundations, scaffolding, and building framework systems
Standards & Certifications
Applications
Where our products deliver proven performance across industries worldwide.
Oil & Gas Wells and Gathering Systems
Seamless casing, tubing and gathering line handle the highest well pressures and sour environments, with no weld seam to initiate cracking downhole.
✓ API 5CT J55–P110, API 5L PSL2
Boilers & High-Pressure Steam
Seamless boiler tubes carry superheated steam at extreme temperature and pressure, where a homogeneous wall without welds is essential for safety.
✓ ASME SA106/SA192, EN 10216-2
Petrochemical & Refinery Piping
Refinery process piping in carbon, alloy, and stainless seamless grades handles hydrogen, sulfur, and high-temperature hydrocarbons per ASME B31.3 design bases.
✓ ASTM A106/A335, B31.3 systems
Hydraulic & Precision Mechanical Tubing
Hydraulic cylinders, honed tube, and precision mechanical components rely on seamless tube for uniform wall and bore geometry under internal pressure.
✓ EN 10305-1 / ST52 honed-ready
Automotive & Bearing Applications
Seamless tube feeds bearing races, steering components, drive shafts and fuel injection systems that demand metallurgical uniformity.
✓ Bearing-grade and case-hardening steels
Structural & Mechanical Engineering
Thick-wall seamless rounds serve heavy machinery, cranes, and structural members where forgings are unnecessary but welded tube is insufficient.
✓ EN 10216-1 / ASTM A519
Frequently Asked Questions
What is seamless steel pipe?＋
Seamless pipe is made by piercing a solid round billet and rolling it to size — no weld seam — giving uniform strength in all directions and the highest pressure integrity.
What manufacturing processes do you use?＋
Hot-rolled (plug mill / MPW / Pilger) and cold-drawn/cold-rolled finishes, with normalizing, quench-and-temper, or solution annealing heat treatments as specified.
What standards does your seamless pipe comply with?＋
API 5L/5CT, ASTM A106/A53/A333/A335/A519, EN 10216 series, ASME SA versions, GB/T 8162/8163 — with EN 10204 3.1 certification.
What size range is available?＋
OD from 10 mm to 720 mm, wall thickness 1–60 mm+; cold-drawn precision sizes to tighter tolerances.
Seamless vs welded — when is seamless required?＋
Seamless is specified for the highest pressures and temperatures, sour service, thick walls, and codes that exclude welds (e.g., high-pressure boiler tubing). For moderate pressures, welded pipe is more economical.
Do you offer sour service and low-temperature grades?＋
Yes — NACE MR0175/ISO 15156 sour service chemistries, and low-temperature grades (A333 Gr.6, EN P11/P12 equivalents) impact-tested to -45°C.
How is each pipe tested?＋
Hydrostatic test, 100% ultrasonic on the body and ends, eddy current for small sizes, plus tensile, flatten, and Charpy tests per lot — all documented.
What is the minimum order quantity and lead time?＋
MOQ typically 5–20 tons for stock sizes, more for special dimensions; stock ships in days, produced sizes in 4–8 weeks. Contact us for a firm quotation.
Can you supply cut-to-length and machined blanks?＋
Yes — cut-to-length, threading, honing, boring, and machined blanks for cylinder and machinery applications.
What documentation comes with my order?＋
EN 10204 3.1 MTCs with heat traceability, NDT and hydro records; 3.2 third-party certification available on request.
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