What are the differences between stainless steel seamless pipes and welded pipes

What are the differences between stainless steel seamless pipes and welded pipes? 

The differences in appearance 

Stainless steel welded pipe 

Due to the use of cold forming process for sheet materials, the steel pipes have high precision, uniform wall thickness, and high brightness on both the inner and outer surfaces (the surface quality of the steel plate determines the brightness of the steel pipe surface), they can be cut to any length, and have a wide range of size specifications. They have particularly prominent advantages in large diameters and thin walls. 

Stainless steel seamless pipe 

The steel pipe has low precision and uneven wall thickness. Due to the limitations of the processing method, the surface brightness of both the inner and outer surfaces of the pipe is low, and the cost of fixed-length production is high. The inner and outer surfaces of the stainless steel seamless pipe are prone to blemishes and black spots, and they are difficult to remove. Usually, the pipe wall is relatively thick. 

2. Differences in the process 

Stainless steel welded pipe 

It is formed by rolling steel plates or steel strips with the help of machinery and molds, and then welded. Depending on the welding method, it can be divided into straight seam stainless steel welded pipes and spiral stainless steel welded pipes. Stainless steel welded pipes have high production efficiency and a wide variety of specifications. Moreover, during the processing of the welded pipes, multiple heating processes are avoided, making the production process more environmentally friendly. 

Stainless steel seamless pipe 

After heating the round tube billet, it is produced through cold rolling, cold drawing or hot extrusion processes. The thicker the wall thickness of this product is, the more economical and practical it becomes. The thinner the wall thickness is, the processing cost will increase significantly. 

3. Differences in cost and price 

Generally, the production cost of stainless steel welded pipes is lower than that of seamless pipes. This is mainly because the raw materials, manufacturing equipment, and processes of seamless pipes are relatively more demanding. However, prices are influenced by the market, so there is no fixed standard for which price is more favorable. 

4 Differences in Basic Performance and Usage 

The seamless pipe will perform slightly better than the stainless steel welded pipe. The specific standards are that the pressure-bearing capacity and strength of the seamless pipe are higher than those of the stainless steel welded pipe. However, in terms of strength and corrosion resistance, it largely depends on the composition of the alloy, so the comparability is not significant. 

Due to its performance characteristics, seamless pipes are mostly used in industrial pipelines. On the other hand, stainless steel welded pipes are more favored by industries such as aerospace, automotive and electronics, which have lower budgets and less stringent requirements.