Properly Deburring (Reaming)

Deburring copper tubing (often called reaming) is the practice of running a blade around the inside of tubing after you cut it to remove the burr edge from the inside.

It's an important practice and should be performed whenever possible. Deburring reduces turbulence inside the lines, as burrs can cause turbulence. HOWEVER…


Whenever possible, point the open end down while you run the blade around the inner edge. Then, tap the line to ensure that the shavings fall out of the line rather than into it. In some situations during repairs, it may make sense to purge nitrogen out the line you are deburring, especially in repair situations, like replacing a compressor, where making the lines point downward may be impossible.

If you are in a situation where you must choose between deburring and possibly dropping shavings into the system, I would rather you didn't deburr.

In the case of making flare connections, deburring is critical. I elaborate on that point further in THIS video showing how to make ductless flares that won't leak. For a flared tube, it is also vital that you don't over-ream the tube and thin out the copper edge. Otherwise, it will be prone to cracking.

In summary…

Deburring is important, but keeping shavings out of the system is even more important.


P.S. – Letting burrs or copper shavings fall into the line set is one of the worst practices I mentioned on my live stream about the top 5 install mistakes that kill systems. You can watch that old stream HERE.


Carroll Price
Carroll Price
8/3/22 at 04:41 AM

This is the quickest and best deburring device I have found for copper or steel tubing. The bits are easy to use with hand drills with size used depending on the size of tubing.

David White
David White
12/7/22 at 12:14 AM

I recently had an AC installed and the installer use a pair of tin-snips stuck into the end of the copper pipe to de-burr. While I initially was concerned — I’ve de-burred a lot of copper tubing using “industry approved” de-burring tools. When I thought about what he did by flatting the burr against the inside wall, the singular question became will be burr be now a rounded edge, or will it possibly break off and circulate through the system. Interested in what other may think.

Related Tech Tips

What's the scoop on PM10 and PM2.5 Particles?
MATLAB Handle Graphics It was December 5th, 1952, only seven years after the end of WWII in London, England, when the “great smog” settled across the city. The “great smog” was the result of a meteorological anomaly combined with unchecked industrial pollution. Still, even once it settled on the city, bringing business to a screeching […]
Read more
Don’t Forget the Service Wrench
One of my most popular YouTube videos goes over how to adjust TXV superheat. It's a very simple little video that I did at my desk, and the other day I got this comment: “Good Video but I hate to say this BUT, with the title SCHOOL, why would you show the public an instructional […]
Read more
Crankcase Heaters and Single-Pole Contactors
We keep two-pole, 40-amp 24v coil contactors on all of our vans. They are versatile and reliable, and you can replace most residential A/C contactors with them. There are a few things to watch for, though, especially when you have a crankcase heater. Many brands power the crankcase heater constantly and shut it on and […]
Read more

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from