We at MWalloys are proud to introduce our Stainless Steel Seamless Pipe—a best‑in‑class solution engineered for rigorous industrial demands. Combining exceptional corrosion resistance with tight tolerances, our pipes ensure reliable performance in applications ranging from high‑pressure fluid transport to structural frameworks.

Grade of stainless steel pipe

Standard of stainless steel pipe

Chemical Requirements (%)

Heat treatment chart of stainless steel pipe

Tensile requirements of stainless steel pipe

Mechanical Properties Comparison

(Room Temperature, Annealed Condition)

Dimensional Tolerances & Common Sizes

(Per ASTM A530, JIS G 3459)

Tolerance Ranges

Standard Sizes & Weights (Round Pipe, Schedule 10S/40S)

Shape-Specific Specifications & Weight Tables

Square & Rectangular Pipes (Per ASTM A554)

Weight Calculation Formulas

• Round Pipe: Weight (kg/m) = (OD - WT) × WT × 0.02491

• Square Pipe: Weight (kg/m) = [4 × Side - 4 × WT] × WT × 0.00795

• Rectangular Pipe: Weight (kg/m) = [2 × (Width + Height) - 4 × WT] × WT × 0.00795

Example: TP304L rectangular pipe 100×50×4mm:
[2×(100+50) - 4×4] × 4 × 0.00795 ≈ 9.14 kg/m

Grade Comparison & Application Scenarios

Comparative Analysis Table

To highlight our edge, we compare seamless versus welded stainless steel pipes:

Quality Assurance and Certifications

We comply with ISO 9001 quality management, ISO 14001 environmental standards, and ISO 45001 for occupational health and safety. In addition, our pipes meet ASTM A312, EN 10216‑5, and JIS G3459 specifications. Third‑party audits are performed quarterly, ensuring every production lot is traceable. Our material test reports (MTRs) document chemical analysis, mechanical testing, and NDT results—providing full transparency.

Technical Specifications & Tolerances

Detailed specs include:

• Nominal Diameters: 1/2″ to 24″ (DN 15 to DN 600)

• Wall Thickness: SCH 5S to XXS (0.065″ to 1.220″)

• Length: Random 5–9 m or cut-to-length per order

• Tolerance: Diameter ± 0.5%; Wall ± 12.5% per ASTM standards

Such tight tolerances reduce assembly issues and support reliable performance in high‑precision systems.

Corrosion Resistance & Surface Finishes

Our pipes undergo chemical pickling followed by passivation in nitric acid baths. This two‑step treatment removes free iron and forms a chromium-rich oxide layer. Consequently, pitting and crevice corrosion are significantly impeded. Furthermore, electropolishing is available for ultra‑clean applications, achieving Ra ≤ 0.4 µm.

Frequently Asked Questions (FAQ)

1. What are the standard material grades available for MWalloys Stainless Steel Seamless Pipe?
   We supply seamless pipes in grades 304, 316, and 321, each conforming to ASTM A312 and EN 10216‑5 specifications. Grade 316, for example, contains 2–3% molybdenum for enhanced pitting resistance in chloride environments.

2. How do I choose between seamless and welded stainless steel pipes?
   Seamless pipes offer superior structural integrity, uniform corrosion resistance, and higher pressure ratings (up to 100 bar) compared to welded alternatives. Decide based on your application’s pressure requirements, surface‑finish demands, and long‑term maintenance considerations.

3. What surface finishes do you offer, and how do they affect corrosion resistance?
   Our standard finishes include pickled-and-passivated (Ra ≤ 0.8 µm) and electropolished (Ra ≤ 0.4 µm). Electropolishing creates a smoother surface that further impedes crevice corrosion, making it ideal for sanitary and high‑purity installations.

4. What are the typical dimensional tolerances for your seamless pipes?
   We maintain diameter tolerances of ± 0.5% and wall‑thickness tolerances of ± 12.5% per ASTM A312. Such precision minimizes assembly issues and ensures consistent performance in tight‑tolerance systems.

5. Can MWalloys Stainless Steel Seamless Pipe be used in high‑temperature applications?
   Yes. Grade 321 is stabilized for elevated temperatures up to 850 °C, making it suitable for heat‑exchanger tubing and exhaust systems. Grades 304 and 316 perform reliably from –196 °C to 800 °C.

6. What testing and certification do your seamless pipes undergo?
   Every lot is subject to mechanical testing, chemical analysis, and non‑destructive examinations in accordance with ISO 9001 and ASTM A312. Material Test Reports (MTRs) document full traceability, ensuring compliance with global standards.

7. How should I handle and install seamless stainless steel pipes to maximize lifespan?
   Store pipes indoors or under cover, use soft slings for lifting, and flush your system before commissioning. We also offer on‑site training to guarantee installations meet best‑practice guidelines and maintain peak lifecycle performance.

8. What environmental benefits do seamless stainless steel pipes provide?
   With over 60% recycled content and lifecycle emissions up to 15% lower than welded alternatives, our pipes support circular‑economy goals and reduce your project’s carbon footprint.

Official References

• Stainless steel – Wikipedia
• ASTM A312 Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
• ISO 9001 Quality Management Systems – International Organization for Standardization
• European Chemicals Agency (ECHA) Database