Lowe's (a big US chain home improvement store) offers black iron pipe cutting and threading services to customers. Basically they sell the pipe & will alter it for you.
From their website in the "We Cut It" section says that they offer:
… pipe threading and cutting for any size
galvanized or black iron pipe. The process involves a machine-based
cutting operation with a metal wheel that creates threads in the ends
of pipes. This service is specifically designed to both thread and cut
pipes. No blade is involved in the process.
I italicized the last part of this statement – what is the significance that no blade is involved? I assume it is important or why would they even bother to mention it?
I'm no expert but do have a little experience cutting threads (manual taps & dies) and from what I'd seen I thought pipe threading was essentially the same thing. But this makes me think I'm missing something?
I need to do some pipework projects soon and mainly I just want to make sure I'm educated well enough to do it right! Thanks
Note – there is a "learn more" link on their website, but it doesn't offer information about this.
Best Answer
When pipe is cut with a blade it can result in material debris and/or metal filings or oxides inside the pipe.
This is equivalent to dangerous sediments or solids in a gas line which can damage or clog equipment. Pipes cut with a blade will likely need to be cleaned and/or flushed before use. Imagine PVC filings clogging a sprinkler head.
Using something like a wheel or die should not pollute the pipe interior.