[header] How to cut copper pipe [title] Select an autocut tool. [step] If you're cutting copper pipe in a tight space (such as up against a corner), use an autocut tool. Measure the diameter of the pipe you want to cut and purchase an autocut tool for that exact size. 
Autocut tools are spring loaded so you won't be able to adjust the size of the cut. [substeps] For example, for a small 1/2 inch (12 mm) pipe, buy a 1/2 inch (12 mm) autocut tool.