SS Seamless Pipe vs ERW Steel Tubes – What’s the Difference

seamless tubes vs ERW tubes

With the rapid development of society and technology, more and more different types of steel tubes, such as welded steel tubes, seamless steel tubes, ERW steel tubes, and so on, are created, and more steel tubes are required. Seamless and welded steel tubes sell well in the competitive steel tube market.

What is SS Seamless Pipe?

SS Seamless Pipe is a stainless steel pipe without a longitudinal weld seam. It is manufactured by forming a solid metal billet and then drawing it through a piercing rod to create a hollow shape. This results in seamless pipes with increased strength compared to welded pipes with weak spots along the welding line. Seamless pipes are ideal for high-pressure applications or avoiding leaks, such as in oil and gas transmission systems.

What are ERW Steel Tubes?

ERW steel tubes are electric resistance welded tubes made from a flat strip of carbon steel, which is rolled up into a tube and then welded together along the length. This process gives them superior strength and dimensional accuracy compared to smooth non-welded tubes. They are commonly used in automotive, furniture, boiler-making, mechanical engineering applications and construction projects.

Visit jyotimetal for more information.

Difference Between SS Seamless Pipe and ERW Steel Tubes

SS Seamless Pipe and ERW Steel Tubes are two types of steel pipes. The main difference is that SS Seamless Pipes are manufactured using a hot rolling process, while ERW Steel Tubes are made with the electric resistance welding process. Consequently, seamless pipes have a higher strength-to-weight ratio than ERW steel tubes due to their uniform wall thickness, making them less susceptible to corrosion and wear and tear over time. Additionally, seamless pipes offer superior pressure containment capacity compared to ERW tubes since they lack potential weld points where failure could occur from areas of weakness.

Variations in raw materials

SS Seamless pipes are made from round steel billets and stainless steel. Hot-rolled coils are used to make ERW pipes. Even though both raw materials are completely different, it should be noted that the quality of the end product – pipes – is entirely dependent on both factors – quality control during the manufacturing process and the initial condition and quality of raw materials. These pipes are made of various stainless steel grades, but the most common are stainless steel 304 Pipes.

Distinctive Manufacturing Process

Heat round steel billets and push them over the piercing rod until the hollow shape is achieved. Extrusion techniques are then used to control their length and thickness. In the case of ERW pipes, the manufacturing process is completely different. The coils are bent axially, and the converging edges are welded with electric resistance welding along their length.

Size Difference

Stainless Steel Seamless Pipes are finished in their assembly line and can be made up to 26 inches in outer diameter. On the other hand, even the most advanced Steel Companies using ERW techniques can only go up to 24 inches in outer diameter.

Differences in Welding Processes

Because seamless pipes are extruded, they have no joints in axial or radial directions. On the other hand, ERW pipes are formed by bending coils along their central axis and are thus welded throughout their length.


In general, seamless tubes are used for high-pressure applications, while ERW tubes are used for low- and medium-pressure applications.

Furthermore, because of the inherent safety features of seamless tubes, they are widely used in applications such as oil and gas, refineries, and other chemical industries where personnel and plant safety must be ensured through zero leakage policies. That said, well-manufactured ERW tubes subjected to strict quality control can be used in services other than water transportation, scaffolding, and fencing.

Manufacturing Process

Electric Resistance Welding (ERW) pipe is made by rolling metal and then welding it longitudinally across its length. Seamless pipe is made by extruding the metal to the desired length; therefore, ERW pipe has a welded joint in its cross-section, whereas seamless pipe has no joint in its cross-section throughout its length.



Recent Posts