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There are a variety of steel pipe options available when it comes to selecting the correct steel pipe for your project. Whether it is going to be used on an oil rig, in a nuclear power plant, or a desalination plant, there are different types of steel pipe that are suitable for each kind of application.

Depending on the application and environmental conditions, you can choose between seamless pipe, forged pipe, or welded pipe. Each has specific advantages, and it is important that you take into consideration all possible factors when choosing the right pipe for your project.

Is Seamless Pipe Stronger than Welded Pipe

It will be understood that engineers will already know what pipe to use, but we still want to be thorough. Let us examine the properties and uses of seamless pipe, welded pipe, and forged pipe to determine which scenario each will work best in.

There are many types of steel pipes available. Seamless steel pipe is manufactured by hot rolling, cold rolling or cold drawn processes, and there is no seam on the pipe body. Welded steel pipe is manufactured by flat steel plates, and there is a welding seam on the pipe body. This includes ERW pipe, LSAW pipe, and SSAW pipe.

How Is Seamless Steel Pipe Made.

In order to be formed by hot rolling, cold rolling, or cold drawing, API 5L and ASTM Seamless Steel Pipes utilize steel ingots or solid drawing tube as raw materials through perforated tubes. For the production of hot rolled seamless steel pipe, billets have to be forged, perforated, rolled, shaped and other processes taken into account. This is normally used for large diameter pipes as well as thick wall seamless pipes. Cold drawn seamless pipes are usually made using cold-drawn forming technology. 

Generally speaking, seamless pipes of small diameters and thin walls are made in this way because the material strength is relatively low. They have a smooth appearance and internal control surface. A seamless steel pipe can be made of carbon structural steel, low alloy structural steel, alloy structure steel, and stainless steel. It is possible to apply seamless steel pipes in numerous industries such as pipelines, thermal services, mechanical industries, chemicals, and so on.

Is Seamless Pipe Stronger than Welded Pipe

How Is Welded Steel Pipe Made

A welded steel pipe, also known as an API 5L or ASTM welded steel pipe, can be made of steel strip or steel plate. These pipes are made with a process that begins with bending the steel plate, followed by welding it into a circular, square or other shape. The manufacturing process is a process called bending the steel plate, then slapping it together. With its high efficiency, low cost and ability to save material, welded steel pipe has been widely applied to a number of industries including aviation, aerospace, energy, electronics, automobiles, and light industries. In the presence of acidic environments, this material has a very high corrosion resistance.

Historical Perspectives And Use Cases For Welded Vs. Seamless Steel Pipe

It is largely due to historical perceptions that ERW and seamless steel piping are viable alternatives today.

Generally, welded pipe was considered inherently weaker because it included a weld seam, whereas seamless pipe was generally considered to be safer and stronger since it did not have this perceived structural flaw. Despite the fact that welded pipe does have a seam that makes it theoretically weaker, manufacturing techniques and quality assurance programs have improved to such a degree that welded pipe will perform according to its specifications when its tolerances are not exceeded. A critique of seamless piping has been raised due to the stretching and rolling processes involved in the manufacture, which produce something other than the precise thickness of steel sheets for welding, which makes the apparent advantages unclear.

There is still a sense of preconceived notions that continue to be reflected in the standards that are governing the manufacture and specification of seamless and ERW steel pipes. A seamless pipe is required for many applications in the oil and gas, power generation and pharmaceutical industries that require high pressure, high temperatures. There is wide acceptance of welded pipes across all industries regardless of temperature, pressure, orpower limiting other variables of the service as long as the parameters noted in applicable standards do not exceed those stipulated by the industry. Welded pipes are generally more affordable and are more readily available.


ERW steel pipe is widely used in structural applications, as well as seamless steel pipe, as neither can be specified interchangeably. Although both can be specified interchangeably, it would not make sense to specify seamless steel pipe when cheaper welded steel pipe can perform equally as well.


What are the benefits of buying seamless steel pipes over other types of steel pipes?

It is because seamless steel pipes are able to withstand extremely high pressure without cracking, which is why most people prefer seamless steel pipes over welded steel pipes. However, seam or welded pipes are unable to do the same as seamless pipes due to the possibility of welded points cracking up under high pressure. It is also very easy to calculate how much pressure there is in seamless pipes. 

Also, seamless pipes are thinner and lighter than welded pipes, and as they are made of uniform extrusions of metal, they are also uniformly shaped. Octal Steel API 5L seamless steel pipe is one of the most durable seamless steel pipes on the market right now, and you should consider purchasing them if you are looking for the highest quality seamless steel pipes.

Is Seamless Pipe Stronger than Welded Pipe

Seamless Vs Welded Steel Pipe Differences Summary

API 5L / ASTM Seamless steel pipe and ERW welded steel pipe have some differences as below:

1. Appearance Difference

Stainless steel seamless pipe is made from spiral steel billet which is a mild steel which is affected by many defects on its outer surface. When it is hot rolled, these defects cannot be eliminated from the billet. These defects are polished after the product is completed.

This welding pipe is made using hot rolled coils as raw material, so the stainless steel coil tubing surface quality of the coil is the same as that of the pipe, making it easy to control. The surface of hot rolled coils has high quality.

Therefore, the surface quality of welded steel pipes is much better than that of seamless steel pipes as a result.

2. Molding Process Differences

During the rolling process, seamless steel pipes can be formed one time from the raw material.

A welded steel pipe is a steel pipe that has been made by bending steel strips or steel plates and then welding them together.

3. Performance And Usage

This is due to the fact that seamless steel pipe has a better pressure capacity and is stronger than ERW welded steel pipe. Therefore, seamless steel pipe is widely used in high pressure equipment, thermal power plants and boilers.

Welded steel pipe usually has a weak spot in the welding seam, and all performance of the pipe is affected by the quality of the welding seam.

A welded steel pipe, on average, is capable of withstanding 20% less pressure than a seamless steel pipe. This reliability is the main reason people choose seamless steel pipe over welded steel pipes. In fact, industrial pipelines are all constructed with seamless pipes only because they are subjected to extreme thermal, chemical, and mechanical loads during their use. Generally speaking, the aerospace, automobile, and electronics industries are more inclined to use welded pipes because the budgets are generally lower, and so is the pressure placed on the pipes.

4. Available Sizes Differences

Most of the seamless steel pipe manufacturers in China manufacture original seamless pipes with a maximum diameter of 20 inches, 508 millimeters. As a result of equipment limitations, the maximum diameter of the seamless steel pipe is usually smaller than 16 inches, 406.4 millimeters. In addition, if a client desires more seamless steel pipe sizes than the above sizes, then hot expanding machining shall be employed. However, the quality of such hot expanded seamless steel pipes usually cannot match that of original seamless steel pipes.

In contrast, welded steel pipe has no such limitations, with a wide range of sizes available from 3/4 inch 48.3mm all the way up to 100 inches 2540mm.In contrast, welded steel pipe has no such limitations, with a wide range of sizes available from 3/4 inch 48.3mm all the way up to 100 inches 2540mm.

5. Cost And Prices

Since seamless steel pipes have the highest cost, they usually are more expensive than welded steel pipes, because they require higher quality raw materials, manufacturing equipment, and manufacturing processes. The jacket materials market pressure can sometimes lead to welded pipe becoming more expensive, so if you come across such a situation, please don’t hesitate to purchase seamless steel pipe of the same dimensions.