A welded stainless steel tube is produced through roll forming strips or sheets of stainless steel into a tube shape and then welding the seam longitudinally. The welded tube can also be drawn similar to seamless tubing to produce a finer weld seam with better surface finishes and tighter tolerances.

Seamless steel pipe has better pressure capacity, strength is higher than ERW welded steel pipe. So it is widely applied in high pressure equipment, and thermal, boiler industries. Generally the welding seam of the welded steel pipe is the weak point, the quality affect overall performance

Steel ERW tubes are generally cheaper to produce due to the simpler process, but this does not mean that they are inferior to seamless ones. The difference in strength, longevity and reliability between the two is not as high as the cost difference may suggest

Seamless BW fittings are manufactured by cutting, heating and shaping seamless pipes into desired forms. Welded buttweld fittings have one, two or more welds, depending on the dimension, the type of fitting and the manufacturing process adopted by the mill.

A seamless fitting is having no joined sections by itself, which is a feature demanded in a few significant applications. If compared, a normal butt weld fitting has one, two or more joins, depending on the shape and dimension, along with manufacturing process.

Seamless tubes are as defined – they do not have a welded seam. The tubing is manufactured through an extrusion process where the tube is drawn from a solid stainless steel billet and extruded into a hollow form.