Tutorial on Cutting Copper Tubing
The process is rather straightforward. Using a tubing/conduit cutter, place the tubing between the cutting blade and the two rollers and tighten the cutter until the blade is just touching the tubing. Then simply spin the cutter around the tubing, tighten the cutter approximately an eighth to a quarter of a turn, and spin it again. Eventually you will cut all the way through the tubing and it will separate. Once you finish cutting the tubing, use the deburring triangle on the back of the tool to smooth the newly cut openings.