Should you choose ERW tube for casing pipe?

Casing pipe is important for a number of projects. It is primarily utilised for protecting utility lines in the ground. The pipes can guard against ground movement, moisture, wildlife, theft, and more. They are also useful for underground construction. However, you need to think carefully about what type of tubing to use. The choice can come down to either ERW tube or seamless. We want to do a little comparison of key factors here to show which is best.

Wall thickness

ERW tubeThe consistency of the walls will always be higher with ERW tubes. This is because manufacturers can start with steel plate, strips, or coils that are accurately sized. So, wall thickness after rolling and welding can be within .05mm. Seamless tubing can’t achieve such a tight tolerance, meaning the deviation can be greater.

Surface quality

It is much easier to control this with ERW tubing. Generally it comes down to ensuring the surface of the coils is right before rolling the tube. It is harder to deal with defects on seamless tube; generally you can only polish after they are made. So, overall ERW is generally best here.


Again ERW performs better in this regards because of how you create the products. You can control the uniformity of the coil, so it can be the same with the tubing. There can be more variance with seamless.


It can be very difficult to control how straight seamless tube is because of how you form it. The longer the section, the bigger the deviation can be. However, there is less concern with ERW tube. You can get the best results with cold working.

Key performance factors

There are several things you need to think about with underground construction and utilities. The most notable are collapse and impact resistance. ERW tubing is the best in both areas. The consistency and uniformity means it does better in anti-collapse testing. If you choose a tough, durable base material, the tube will have excellent toughness. You can further improve this and the ability to resist impact by controlling the quality of the edge and welding parameters.


A big advantage with ERW is it can be longer and have much bigger diameters than seamless. In turn, that can have a huge impact on costs. It also helps that ERW tends to be cheaper initially too. So, when cost is a concern, choosing welded tube is the better option.

Ordering high quality ERW tube

The crucial thing with casing pipe is to use high quality products. That will ensure you get the best protection for utilities and the right performance for underground construction.

Union Steel Tubes is one of the UK’s top ERW tubing experts. We have years of experience here, ensuring we can offer tube for a massive selection of applications. More importantly, we always work to high standards to make sure our clients are happy.

So, if you want ERW tube please speak to us. We can help you choose the perfect products for your application.