Plumbing Technique: Cutting PVC Pipe - Various Methods

By Bruce W. Maki, Editor

Start:

Most plumbers I've worked with cut PVC pipe with an ordinary hand saw. For the smaller sizes of PVC pipe (2" and less) I sometimes use an old-fashioned miter box and back saw.

Any common wood-cutting type of hand saw should work, as long as the teeth are not too fine. These are medium-sized teeth on this back saw... there are about 13 teeth per inch.

For example, the teeth on a hack saw are too fine... they will just gum up and you'll be wasting your time.

Cutting PVC The Easy Way: For years I have cut PVC pipe on a miter saw... but this has risks. The saw blade must be lowered VERY SLOWLY* into the plastic or else the blade will GRAB and tear a chunk out. Then the chunk will bounce off the saw fence and hit you. I've had this happen. A fine-tooth blade works better than a large-tooth cross-cut blade and cutting can be done faster... but still not as fast as cutting wood.

*How slow is "very slow"? A piece of wood similar to a 1½" pipe could be cut safely in 2 or 3 seconds. I estimate that I take 20 to 30 seconds to cut this size of PVC pipe with a miter saw. Consider one-tenth the plunge rate to be a rough guide to safely cutting PVC pipe on a miter saw.

The Blade Is Everything: The 7¼" blade on this inexpensive miter saw has 40 teeth. I guess these saw teeth would qualify as "medium sized".

Years ago I had a 10-inch miter saw with a very fine toothed blade... the teeth were almost as small as the back saw shown previously. The teeth were steel, not carbide. That blade worked very well for cutting PVC pipe because each tooth was only removing a small chunk of plastic... it rarely had the problem of tearing out a chunk.

Actually, when the teeth got dull the blade would cut plastic better. For cutting plastic, some people use a very-fine-tooth blade installed backwards. This is commonly done for cutting vinyl siding, which is tricky to cut because it's so thin. I doubt the backwards blade helps much when cutting the thicker plastic pipe such as drain-waste-vent or schedule 40, but it might make a big difference when cutting thin-wall pipe. Such pipe is sometimes used for plumbing drain lines (e.g. 3.25" OD drain pipe) or outdoors for landscape drainage.

De-Burring The Ends:

While this isn't necessary, I like to remove the burr from the cut ends of PVC pipe. De-burring the end seems to make the pipe slide into the fitting hub easier.

I simply use a sharp knife as a scraper. Here I'm sliding the knife sideways across the outer surface at the end of the pipe.

On the inside I do the same thing... slide the knife sideways like a scraper. In fact a sharp paint scraper works well for this.

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Written July 31, 2007