Why is hot finished tubing better than cold formed?

To an untrained eye, one piece of metal tubing may appear the same as another. However, if you really look there can be some huge difference. For example, there may be inconsistencies in the shape and thickness. The level of finishing could differ greatly too. We want to have a closer look specifically at hot finished and cold formed ERW tubes today. There are crucial differences here to keep in mind.


ERW tubesTo begin with, let’s look at how manufacturers make each type of tubing.

Cold formed is the basic process to make a tube. You take a strip of steel, roll it to create the shape, and then weld to join the edges. That is pretty much all it takes, and you have a simple tube.

Hot finished tube begins with the same process to create the basic tubing. However, there is then additional processing to the tube and weld zone. This involves heating the tubes to high temperatures, sometimes up to 1,000 Celsius. The manufacturer then cools them carefully. What this does is help to remove internal stresses and correct inconsistencies.

The best choice

There are many situations where simple low cost ERW tubes are sufficient. For example, they can work for building applications and some pipelines. However, there are drawbacks. The presence of a heat affected zone around the weld, higher internal stresses, and inconsistencies in shape and properties can lead to installation, performance, and service life issues.

Hot finished tubes are a better option if you need uniformity and consistency. They can provide easier installation, better mechanical properties, and a longer service life. Most crucially, they are generally much safer to use.

One area where you should avoid cold formed tubes is high pressure pipelines. The drawbacks with them mean there is a chance of catastrophic failure when the lines are pressurised. Guidelines typically now state the tube and weld zone should have the same properties. As a result, you usually have to select hot finished tubing or seamless. The latter can be more costly though and may have issues with consistency.

Do you need quality ERW tubes?

Union Steel Tubes is a specialist with years of experience. We create quality tubing for numerous applications. The standards here are very high because we focus on consistency and tight tolerances.

If you ever need tubing for any kind of project, we recommend you speak to us. We can share our knowledge and help you to select the right products. It may be that you would be perfectly fine with basic tubing. However, there could be a risk of issues like failures and downtime. If so, you may be better with higher quality ERW tubes. We’ll help you consider all aspects and decide on the right tube.

So, why not contact us and get professional advice? It could ensure the best results for your budget and project.