What is the Difference Between Stainless Steel Seamless Tube and Welded Tube?

Stainless steel tubes are fundamental components in numerous industries, from petrochemical and energy to pharmaceutical and food processing. A recurring question among procurement professionals revolves around seamless vs welded stainless steel tube selection. This guide demystifies their differences while highlighting actionable insights for material selection.

Stainless steel seamless tube and welded tube have distinct properties, advantages, and limitations depending on the application. At Ganyeah Group, we understand the critical importance of material selection and offer both types, manufactured to meet stringent international standards.

ASME B36.10 super duplex ASTM A790 PE Stainless Steel Seamless Tube

Manufacturing Process

The most fundamental difference between stainless steel seamless tube and welded tube lies in the manufacturing methods:

Seamless stainless steel tubes are manufactured through a solid billet extrusion or piercing process, where the tube is formed without any welding seam. This results in a uniform structure throughout the tube body.

Welded stainless steel tubes, in contrast, are produced by rolling stainless steel coils into a tube shape and then welding the seam using TIG, laser, or high-frequency electric resistance welding (ERW). The weld zone is often heat-treated and cold worked to restore mechanical properties and ensure dimensional integrity.

Strength and Pressure Resistance

Stainless steel eamless tubes are often selected for high-pressure applications because they offer superior uniformity and strength, especially under internal stress. For instance, a seamless 316L stainless steel tube with a 1″ outer diameter and 2 mm wall thickness can typically withstand burst pressures over 6,000 psi, whereas a stainless steel welded tube of the same dimensions might rate around 4,000–5,000 psi, depending on the welding quality and post-processing.

For general applications where extreme pressure is not a concern, welded tubes are more than sufficient and comply fully with ASTM A249, A269, or A358 standards, depending on class and grade.

Corrosion Resistance

When it comes to corrosion, both types offer excellent performance when made from high-quality stainless steel such as 304, 316L, or 904L. However, stainless steel seamless tubes eliminate the weld seam, which is often the most vulnerable point in terms of localized corrosion—especially in chloride-rich environments like marine, desalination, or offshore oil operations.

That said, with modern welding techniques and post-weld heat treatment (solution annealing), stainless steel welded tubes can reach comparable corrosion resistance, provided the manufacturing is tightly controlled—something Ganyeah Group guarantees through 100% PMI and IGC testing.

Stainless Steel Weld Tubes

Dimensional Precision

Stainless steel welded tubes generally offer better dimensional control due to the use of cold-rolled strip, which ensures tighter tolerances on wall thickness and diameter—typically within ±0.1 mm. Stainless steel seamless tubes, while stronger, are more difficult to control dimensionally, particularly over long production runs or large diameters.

For applications like instrumentation, architectural tubing, or heat exchanger coils—where exact outer diameter and wall thickness are critical—welded tubing is often preferred.

Cost Efficiency

Stainless steel welded tubes are typically 20–40% more cost-effective than seamless tubes of the same grade and size. This is because the raw material (strip/coil) is cheaper, the manufacturing process is faster, and the yields are higher. For large-diameter pipes (above 8″ or 219 mm), the cost difference becomes even more significant, with welded pipes offering a more economical solution without compromising on structural performance for low to medium pressure applications.

Application Suitability

Final Thoughts

Both seamless and welded stainless steel tubes have their rightful place in industrial applications. The choice should be based on operating pressure, corrosion exposure, budget, and dimensional requirements.

At Ganyeah Group, we produce and supply both types under strict quality systems, including ASTM A213, A269, A312, A358, and ASME SA standards. Whether you need corrosion-resistant seamless tubing for an offshore platform or precision-welded tubes for a food processing plant, our engineering team can guide you through specification, selection, and compliance.

Contact us today to learn more or to get a technical consultation tailored to your project.