There are a number of ways to cut copper pipe and the least recommended of these is to cut with a hacksaw. Granted it is the cheapest of the tools we can offer but when a copper pipe is cut with a hacksaw there is a lot of movement in the pipe. It does not matter how strong you are, you will not be able to hold the pipe completely still while you cut. This is not a disaster if you are cutting a new piece of pipe for a new system. If the pipe is already part of a system, be it a hot or cold water pipe, or a central heating pipe, as it moves while being cut it will put pressure on the nearest joint allowing the possibility of that joint to fail.
The second reason for not using a hacksaw is because however fine the blades teeth are it will leave burrs on the cut end of the pipe. These burrs will stop the fittings sliding nicely onto the pipe and the pipe will need to be filed smooth. When you are in a tight corner of a room, with no room to move, never mind use a hacksaw and file, this is not a great way to do any kind of plumbing.
The answer? Wonderful tools called pipe cutters and pipe slices.Both use a hardened wheel to cut into the pipe rather than a toothed blade. A pipe cutter, shown on the left, is placed over the pipe and the handle, or knob, at the top is turned clockwise until it closes down onto the copper. The cutter is then turned fully around the circumference of the pipe where it will score the pipe cutting into it slightly. The knob is then tightened a touch more and the cutter turned round the pipe again. The cutting wheel goes in a little deeper and the operation is repeated until the pipe simply drops in half. The cut end is left clean and burr free and the minimum effort has been used. The pipe cutter in the image is adjustable to cut pipes from 8mm to 38mm.
Even easier, and absolutely wonderful for tight spaces is a pipe slice, shown right. The pipe slice operates on exactly the same principle as the pipe cutter but the blade, or cutting wheel is spring loaded. The pipe slice is pushed onto the pipe in the correct place and is simply turned. As you turn, the wheel cuts into the pipe and the spring applies just enough pressure to push it it a tiny bit more. Keep turning, the slice keeps cutting and seconds later the operation is complete. Once again the end of the pipe is neatly cut with no need for files or wire wool. The only downside to a pipe slice is the fact that you need a different pipe slice for every diameter of pipe you need to cut but, at home, the average DIY enthusiast will only ever want to cut either 15mm or 22mm pipes and these little beauties are not expensive. Click on any of the images to learn a little more and buy the tools if you want to.
Check out our video section on soldering copper pipes to watch a short demonstration on how to cut copper pipe correctly. There is also an excellent two part video on how to solder copper tubing correctly.