Steel pipe versus copper pipe: What are the main differences?

The question of copper pipe versus stainless steel arises often, notably in plumbing.

Is there a significant difference of one over the other? Are there major cost differences? Does it make any difference during installation?

Let’s take a look.

Steel is one of the strongest and most durable metals available for plumbing. When building a home or renovating your plumbing system, you want to make sure that you don’t have to revisit this again any time soon. It’s a big job.

Therefore, making use of steel fittings which will last the life of the building is a good idea. Steel can withstand rust and corrosion exceptionally well, and remain largely unaffected by temperature variances. In areas of extreme cold where water is likely to freeze in the pipes, the steel is most often able to withstand the internal pressure without splitting or cracking.

With steel being as tough as it is, it does make it more difficult to work with for plumbing purposes. This makes installation a longer and costlier process – or at least one done by a professional who knows the personality of steel piping. If steel is going to be used in plumbing, then it will need to be galvanised. However, if your water supply is treated with chlorine, this may leach traces of lead into the water supply over time. Certain grades of steel are more resistant to chloride corrosion, such as 316/316L, so the type of steel that you are using in these areas will matter.

Copper piping, by contrast, is a softer, more malleable metal. It can be bent to shape which negates the need for additional fixtures and fasteners. However, copper plumbing fittings can be more costly than steel fittings so it’s worth doing your homework.

Copper offers excellent resistance to bacteria and rot which assures a safe and clean water supply. Copper, however, doesn’t hold up as well in extreme cold. If water freezes in copper pipes it can cause leaking and splitting. A point to note is that if you live in an area with high water acidity then you will find that the copper piping will corrode.

Of course, besides copper and steel pipe, PVC is also a good option for plumbing – albeit not as strong. Your choice of piping will depend on your budget, your area and (of course), the aesthetics of the building.

At Steelmor we specialise in fabrication, welding and rolling of steel pipes to your specifications. Give us a call on (011) 747 5700 or visit our website at for more information.