317L Round Bar

What Is Seamless Stainless Steel Tubing and What Are the Advantages?

It is necessary to have a mechanism in order to force a hole into a billet in order to make seamless tubing. Seamless tubing does not have a longitudinal weld seam. The seamless meaning pipe is manufactured without welding at any stage. When welding pipe, no filler is added during the welding process.

 As a result, rotary piercing and rolling are considered to be the most popular method today for manufacturing seamless tubing. It is the process of heating, piercing, and working a steel round bar that has been conditioned. As the tube is forced to flow around a piercer point, it creates a hollow billet which is supported by a mandrel or plug, while the billet roller is extended. Additional rolling on the outside diameter of the steel tube is required to size it.

 In addition to this, seamless tubing can withstand a pressure up to 20% higher than welded tubing of the same material and size due to the absence of welded seams. Welded and drawn tubing may also have visible seams that can be a problem for the user.

 Asst tube is able to provide superior corrosion resistance thanks to the fact that it does not contain any impurities, which is one of the advantages of seamless tubing. It is possible to avoid defects and differences in malleability that may occur in welded tubes if you choose seamless tubing instead of welded tubes. There is a large difference between seamless steel pipe and welded tubes because

seamless tubes do not require testing for the integrity of the weld, unlike welded tubes.

Therefore, seamless pipe is often more suitable for critical applications.

What Is Welded Stainless Steel Tubing and What Are the Advantages?

It is the first step in the production of a welded tube to roll a steel coil to a thickness that corresponds to the desired gauge thickness. The strip is then rolled into a coil, then cut into a width that corresponds with the size of the tube that needs to be produced. After this is completed, the coil of the flat strip is formed.

 In order to form a tube, a cut coil is passed through several rollers, and then the tube is then welded in a chemically neutral environment during a rolling process. In order to forge the welded seam in the tube, a rolling process is used, followed by a heat treatment process in order to finish the welded tube. As soon as the tubes have been welded together, they can be drawn over mandrels and ground if necessary so that the welded seams are smoothed and make it almost impossible to observe from a distance.

 Because welded and drawn tubes require less drawing and annealing to make than seamless tubing, they can be much cheaper to produce than seamless tubing. Since welded and drawn tubes are produced in a less time-consuming manner, they are significantly cheaper to make than seamless steel tubes. The tubing is also available much more quickly than seamless tubing (although there are many ways to reduce this lead time by stocking intermediate-size seamless tubing starting stock along with it).

Seamless Vs Welded Stainless Steel tubing

Welded Vs Seamless Stainless Steel Tubing

There is a great deal of versatility in stainless steel tubing in manufacturing and fabricating, as it is one of the most versatile metal alloys available. The tubing consists of two main types; seamless tubing and welded pipe. It is primarily dependent upon the application requirements of the product whether seamless tubing or welded tubing should be used. There are two possibilities when it comes to choosing which tubing to use, and it is important to remember that first, the tubing has to comply with the specs of your project. Secondly, the tubing must also comply with the conditions of use to which it will be put.

Seamless Tubing Manufacturing

There is also a distinction between welded and seamless tubing, so you can use this distinction to determine which tubing is most appropriate for your application. From the names of seamless tubes and welded tubes, it is evident that there are different ways that seamless tubes are manufactured and welded tubes are manufactured. Seamless tubes are defined by the fact that there is no welded seam pipe in their tube. An extrusion process needs to be used in order to manufacture the industrial tube and steel, as it must be drawn from a solid billet of stainless steel and then formed into a hollow form. It is after the billets have been heated to the correct temperature that they are formed into oblong circular molds that are hollow in a piercing mill. The molds are drawn through a mandrel rod as they are hot and elongated in order to form a seamless tube. To achieve this, the molds are extended by twenty times more than they would normally be. There are three final shaping processes that need to be done with the tubing. Pilger, cold rolling, or cold drawing are the three.

Welded Tubing Manufacturing

Stainless steel welded tubing is formed by rolling strips of stainless steel into tube shapes and making a seam longitudinally around the entire length of the tube. There are two methods used for forming welded tubing: hot forming and cold forming. In contrast to hot forming, cold forming produces a more uniform seam across the entire length of the tube. In comparison to both hot and cold forming methods, cold forming produces a smoother finish and can be more precise in terms of tolerance. Regardless of the method used to create a steel tube, there is no doubt that each method will produce a steel tube that is strong, durable, corrosion-resistant, and durable. Depending on the shape that is needed for the seam, you can either leave it as a beaded seam or you can further shape it using cold rolling and forging methods in order to give it a more refined appearance. A seamless tube can be drawn in the same manner as welded tubing so as to produce a finer weld seam, with better surface finishes, and more precise tolerances than welding tubing. This is also possible with welded tubing because seamless tubing can be drawn similarly to welded tubing.

Choosing Between Welded and Seamless

It is important to remember that there are advantages and disadvantages to choosing between seamless and welded tubing.

Seamless Tubing

Because seamless tubes are composed of completely homogeneous tubes, they can withstand higher pressures than welded tubes, so they can be stronger, corrosion resistant, and more able to withstand greater pressure than welded tubes can. Because seamless tubes are completely homogenous tubes, by definition, they are able to withstand higher pressure than welded tubes by definition. Therefore, they are able to survive harsh environments and critical applications more effectively than welded tubes.


  • Stronger
  • Superior corrosion resistance
  • Higher pressure resistance


  • Oil and gas control lines
  • Chemical injection lines
  • Below sea safety valves
  • Chemical processing plant steam and heat trace bundles
  • Fluid and gas transfer

Welded Tubing

Due to the fact that welded tubing is typically less expensive than seamless tubing, the manufacturing process is generally simpler. A standard size of welded tubing, like seamless tubing, can also be manufactured with similar lead times, depending on the number of orders. As with seamless tubing, it can also be manufactured in long continuous lengths. The cost of seamless tubing can be reduced by choosing smaller manufacturing runs if fewer quantities are required. It does affect the total cost of seamless tubing in the long run. I find it more expensive to manufacture and deliver custom-sized seamless tubing than to manufacture and deliver standard tubing.


  • Cost-efficient
  • Readily available in long lengths
  • Fast lead times


  • Architectural applications
  • Hypodermic needles
  • Automotive industry
  • Food and beverage industry
  • Marine industry
  • Pharmaceutical industry

Both Seamless and Welded Tubing Must Meet Pressure Standards

It is the standard specification for seamless and welded austenitic stainless steel tubes that have been developed by ASTM International for general application purposes as outlined in ASTM A269 in accordance with the ASTM International standard specifications. As part of the standard, manufacturers are required to comply with the chemical composition specifications and the hardness requirements for various grades of tubes are specified as part of the standard.


A nondestructive electric test or a hydrostatic test must also be performed on seamless and welded steel tubing in order to ensure that the tubing does not fail when pressure testing according to ASTM A269. The standard specifies the maximum tensile stress limits that may be applied to tubing with variable outside diameter and wall thickness, according to which the tubing may be tested.

Mokshi Shah
Mokshi Shah