Stainless steel seamless pipes and seamed pipes, these two types of pipes are widely used in the industrial field. The differences and advantages and disadvantages between them are crucial to choosing the right pipe material. Stainless steel seamless pipes, due to their integrated manufacturing process, have higher strength and corrosion resistance and are widely used in high pressure, high temperature and corrosive environments. In contrast, stainless steel seamed pipes are usually more advantageous in price, but their strength and corrosion resistance are slightly inferior to seamless pipes. In specific applications, it is necessary to choose the appropriate pipe type according to actual needs and budget.

In the industrial field, although stainless steel seamless pipes and seamed pipes are both important types of coil materials, there are significant differences between them. These differences are not only reflected in the visible aspects, but also involve the performance, quality and application range of the pipeline. Therefore, when choosing, we need to make a comprehensive consideration based on actual needs to ensure that we can make a more sensible decision.

1. Seamed stainless steel welded pipes are generally better in quality than stainless steel seamless pipes. This is because seamed stainless steel pipes are made of high-quality steel plates that have been precisely cold-rolled, and their defects are mainly concentrated in the welding parts, which are easy to detect and repair. In contrast, seamless pipes are stamped from stainless steel billets, a process that can cause numerous tears in the pipe wall, affecting its overall quality. In addition, eddy current testing shows that the defective rate of seamed stainless steel pipes is often lower than that of seamless stainless steel pipes. At the same time, in ultrasonic testing, defects in seamless pipes are often difficult to detect due to the large background noise; in contrast, the background noise of seamed stainless steel pipes is low, making defect detection relatively easy.

2. The manufacturing process of seamless stainless steel pipes involves punching a hole in a stainless steel billet at a high temperature of 2200°F (1200℃). At this high temperature, the tool steel becomes soft due to stamping and drawing, and is formed spirally through the hole. This process results in uneven pipe wall thickness and high eccentricity. In contrast, stainless steel seamed pipes are made by precision cold-rolled plate process, with extremely small wall thickness tolerances and highly uniform wall thickness throughout the circumference.

3. Different pressure bearing capacity: Seamed pipes can generally withstand a pressure of less than 20 kg, which is a relatively reliable range of use. It is generally used for low-pressure fluids such as water, gas, and compressed air; seamless pipes can withstand ultra-high pressure, and of course their wall thickness will increase accordingly, which needs to be designed according to pressure requirements. It is generally used for high-temperature and high-pressure equipment such as high-pressure oil pipes and boiler pipes. There are also seamless pipes for structural use, which depends on the design requirements.