Using a pipe bending spring is the cheapest and simplest way to put a bend in a piece of copper pipe. As a general rule, the minimum bend radius should be equal to 4 times the outside diameter of the tube.Tube diameter 22mm – minimum bend radius = 88mm
Tube diameter 15mm – minimum bend radius = 60mm
Internal pipe bending springs
Step 1 – Select your pipe
Select the piece of copper pipe you wish to bend.
A longer piece of copper pipe will be easier to bend compared to a very small piece, as you will be able to apply more leverage. It is always best to bend a longer piece and then cut it down to size afterwards.
Step 2 – Deburr the end of the pipe
If your pipe has been previously cut with a pipe cutter tool, the cut end may curve slightly inwards and you may not be able to fit your spring into the end.
If this is so, either deburr the end of your pipe with a deburrer or widen the hole with a reamer until the hole is big enough. Alternatively, you could cut the end off with a hacksaw.
Step 3 – Feed the spring into the pipe
Once the end of your pipe will accept the spring, feed it down into the pipe, tapered-end first.
Oiling your bending spring before you insert it will make it easier to retrieve from your pipe at the end of the process. If your pipe is to be used on drinking water, use olive oil.
Step 4 – Leave a little bit showing
Make sure you leave a small amount showing so that you can retrieve it again afterwards!
If you need to insert the pipe bending spring all the way into your pipe, attach a piece of strong string or wire to the ring end so that you can pull it out again.
Step 5 – Bend the pipe
Locate the place at which you want your bend to be and place it against your knee.
Gently pull back on the ends of the pipe until the desired angle is created. If you pull back too quickly or violently you risk creasing the pipe. Copper is a soft metal and should not need a great deal of strength to bend it.
Wonkee Donkee TOP TIP
Because it can be difficult to remove the spring when you have reached your desired angle, it is advised to over-bend slightly and then slacken it off a bit. This will make the spring easier to retrieve.
Step 6 – Pull the spring out
Retrieve your spring from inside the pipe.
If you find this difficult, you can slip a tommy bar (or screwdriver) into the ring end and twist it clockwise to slacken the springs.
Your job is complete!
External pipe bending springs
If you need to bend a pipe that has a diameter smaller than 15mm then you should use an external pipe bending spring.
Step 1 – Feed the pipe into the spring
Feed the pipe into the spring via the wider tapered end.
Step 2 – Bend the pipe
Apply pressure to the ends of the pipe and gently form the desired bend. Bending too quickly or violently will result in a creased or rippled pipe.
Step 3 – Slide the spring off
Slide the spring off the pipe. If you find this difficult, try twisting as you pull to slacken the springs.