See all Blog Posts What is a Seamless Tube? Category: Aluminium, Hints and Tips, Pipe, Stainless Steel, Tube Posted: January 30, 2025 Tube is one of the key material shapes used across the industry, from carrying everything from oil to air and also being used as structural members in buildings, car safety systems and more. When selecting a tube for your project, it’s important to know the different types and their drawbacks. In this article, we discuss what Seamless Tube is, and how it differs from other types. What is a Seamless Tube? As the name suggests, a seamless tube is a round tube without a welded seam at any point in its circumference. It is made using an extrusion process that does not require the joining of two ends, unlike other types. There are a few different types of seamless tube, mainly determined by the temperature the material is at during the final processing steps, Cold drawn seamless tube (CDS) and Hot Finished Seamless Tube (HFS) are both prominent examples. What Is The Difference Between Seamless Tube And Welded Tube? Seamless tube is not made using a welding process, and as such has no seam or joint. It is therefore one homogenous material, and as such does not contain any weak points or potential weld defects that can theoretically be present in welded tubes. Seamless tubes are also often more dimensionally accurate and hold superior mechanical properties when compared to welded tubes. What is the Alternative to Seamless Tube? Electrical Resistance Welded tube is the main alternative to a seamless tube, it is made by forming a flat sheet strip into a circular shape, then welding the edges together before rolling to a final dimension. It provides a cost-effective and durable tubular product, but the welded region will always provide a weak point, making it inferior to seamless tubes in mechanical and metallurgical terms. How is a Seamless Tube Made? Seamless tube starts with a heated billet of steel, which is processed in a piercing mill, where an initial hole is made, the steel is then passed through a series of progressive dies and rollers to bring it to its final shape. During the process, the billet will stretch to over 20 times its original length. Once the rough tube shape is formed, either hot or cold rolling is performed to bring it to its final dimension. Cold rolled tube is more dimensionally accurate and generally has better mechanical properties, hot rolled tube is more cost-effective and sport a blackened, scaled finish. Benefits of Seamless Tube Higher strength – welding involves a heat-affected zone and potential inclusions and impurities, this means the process of creating a welded tube is not as easy to control, and therefore seamless tube is generally of better quality and has better mechanical properties. Surface finish – the cold drawing process in particular results in a much cleaner finish when compared to the hot processing of some welded tubes, requiring less processing to use in aesthetic or hygienic applications. Better pressure rating – because of its superior mechanical strength and homogenous structure, seamless tubes can be used for pressurized systems more readily. What Metals is Seamless Tube Available In? Mild Steel – One of the most commonly used materials for construction, architectural and structural applications, there are typically a few different grades available, each with slightly different strength properties. Stainless Steel – Seamless stainless tube is invaluable to many industrial applications, providing a high strength and hygienic pipework material. Aluminium – Most aluminium tubes and shapes are seamless through ease, as the material is very easy to extrude, although welded tubes in aluminium are used. Applications of Seamless Tube Oil and gas – thanks to its high strength, tube used in processing applications for the oil and gas industry are almost always seamless Structural steel – Components like tension bars, roof trusses and even beams are often made using seamless tube. Its homogenous nature allows it to be easily formed for things such as stadium trusses. Food Production – Stainless seamless tube is vital to the food and beverage industry, ensuring hygienic internal surfaces. Get Seamless Tube at Metals Supermarkets Whether you need seamless, welded, stainless or mild steel tube for your next project, Metals Supermarkets will be able to help, with stores nationwide and an excellent cut-to-length service. Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with 125 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminium, tool steel, engineering steel, brass, bronze and copper. We carry a wide range of shapes including: bars, tubes, sheets and plates. We can cut metal to your exact specifications. Visit one of our 8 locations in the United Kingdom today. Share: Facebook Twitter LinkedIn E-Mail Tags: aluminium, stainless steel Related blog articles What is the Difference Between Yield Strength and Ultimate Tensile Strength? What is Surface Hardening? What does Thermal Conductivity Mean?