ERW Mills

Electric resistance welding, or ERW, is a welding process that manufactures steel by cold-forming sheets into, round, square, rectangular, octagon and several other shapes and sizes. The end result of the ERW pipe and tube process produces material that can be used for many engineering purposes.


At Kahn steel, our finished goods have gone into a variety of applications; we primarily produce material for; fences, gates, panels, feedlots, and corrals. Furthermore, we have manufactured material used for constructing arenas and solar panels. Other common finished goods produced by ERW mills can be found in structural applications such as bollards and foundation repair.


The ERW pipe making process starts with coiled steel. This material has an appropriate thickness, and specific width, to form into pipe that molds to its relevant specifications. The slit gets pulled through a machine where a series of rollers gradually shapes the steel into a cylindrical tube. The edges of the tube now form a cylinder as it comes together. At this point, an electric charge is applied at the appropriate spots which heat the edges so they can be welded together. The process is high-speed and gets made in continuous lengths.


Contact us today to get your tube rolled to length and packaged to your specifications.





Steel 101: Difference Between Pipe and Tube


For any individual who is foreign to manufacturing and engineering, the terms ‘pipe’   and ‘tube’ might initially come across as identical. And in many ways, pipes and tubes are similar. However, with a little more familiarity with the characteristics and properties of the two, there are several ways to differentiate between pipe and tube.




According to the National Association of Steel Pipe Distributors (NASPD) Pipe is a cylindrical conductor, manufactured from steel, with a hollow inside.


When trying to determine measurements and sizes for steel pipe, it is important to remember that pipe size follows an industry standard, so the sizing is always going to be identical, regardless of the steel grade. There are four dimensions relevant to the measurement of steel pipe: Inside Diameter (ID), Outside Diameter (OD), Wall Thickness and Length.






The American National Standards Institute (ANSI) established that steel pipe is measured by Nominal Pipe Size (NPS). NPS is specified by two designations, the diameter of the pipe based in inches, and a schedule for wall thickness. NPS of 1/8 of an inch through 12-inch NPS are identified by their nominal inside diameters. On the other hand, pipe that is larger than NPS 12” are identified by their nominal outside diameters and are considered Large OD pipe.         




On the other hand, there’s tube. Tubing is a hollow shaped product with a relatively uniform wall thickness. Tube can be manufactured rounded, square, rectangular or octagon to name a few. Tube can also be manufactured to specified requirements for dimensions, chemical analysis, mechanical properties and countless other mechanisms.

Some of these mechanisms include tube being manufactured into lengths for various applications, including machinery and gates, panels, corrals, fences, feedlots, structural applications and various other projects. Tube can either be hot rolled steel or cold rolled steel.