Steel tubing is perfect for a number of needs, including pipelines, railings, furniture, and much more. However, there are many different types. Two of the most interesting are ERW tubes and SSAW tubes. We want to have a look at the two here with a comparison of how they are made and crucial differences.
It is relatively straightforward to create ERW tube. You begin with steel strips or coils. There are rolled to create the tubing. There is then electric resistance welding to heat the edges and pressure to force them together to bond.
SSAW tube (spiral submerged arc welding) also begins as coils or strips. However creation is not as simple as rolling. Instead, the raw steel needs to be adapted into a spiral shape. There is then welding to join the edges throughout.
ERW tubes provide some really impressive advantages over SSAW. Firstly, high frequency welding can be fast, efficient, and consistent. You don’t need any filler material and the heat affected zone (HAZ) will be small. Plus, there won’t be a weld pool. Most importantly, the tubing can have very high geometric accuracy.
All of this doesn’t mean that SSAW doesn’t have its own positives though. The major one is you can use steel strips to create tube with different outer diameters. There is more flexibility here than with ERW. The welding also means the seams won’t follow the main direction of the stress.
One of the most important things here is ERW tubes are cost effective. Producers can create them quickly in large batches. There are also no additional costs for filler material.
SSAW tubes are more expensive for a number of reasons. Firstly, it requires more inputs to shape the tubes. Then it is more time consuming to do the welding. Plus, you need to pay for the filler material for the welds.
A crucial thing with any tubes is to consider the residual stress. The last thing you want to do is overlook this and find out it is too high and the tubing might fail. If that did happen, it could cause a massive accident.
The residual stress is higher in SSAW tube and can cause some concerns. ERW tube does have high stress, but the geometrical accuracy helps to address it. Plus, proper heat treatment can help to eliminate it.
Do you want to order exceptional ERW tubes?
Union Steel Tubes is one of the most reliable names if you need tubing. We specialise in ERW, so we know the ins and outs of the technique. More importantly, we can safely say we have mastered it and can deliver high quality tube on a consistent basis to suit many needs. We also have a massive selection of options to help with this.
If you need ERW tubes, you should speak to us. Get in touch today if you need more info or want recommendations for different projects.