# Sharp pipe thread



## Dylan JC Buffum (Jun 9, 2019)

I’m using 1/2” black iron pipe in a project. I bought the parts online, and the three dozen 1” nipples I got have razor sharp threads, and the inside edges are also sharp. I’m running lamp wires through them, so this needs to be fixed.

Any idea how to soften them a bit so they don’t slice my fingers or the wire insulation? I’ve been wearing leather gloves while handling them.

On the inside edge I tried a small tapered grindstone drill bit in my press, which is ok but not great. I can hand file the inside, but that would be time consuming.

On the outside I tried a steel wire brush in the drill press, but it was useless. I don’t think filing the threads is an option.

I can’t think of any way to use my bench grinder for this job. I have a dremel; maybe there’s a good bit for this job?

It almost seems they should be tumbled in a slurry of sand and oil. But I can’t think of a way to do that with the available tools.

Any bright ideas?


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## Dave McCann (Jun 21, 2020)

Dylan JC Buffum said:


> I’m using 1/2” black iron pipe in a project. I bought the parts online, and the three dozen 1” nipples I got have razor sharp threads, and the inside edges are also sharp. I’m running lamp wires through them, so this needs to be fixed.
> 
> Any idea how to soften them a bit so they don’t slice my fingers or the wire insulation? I’ve been wearing leather gloves while handling them.
> 
> ...


A tapered pipe reamer is the proper tool to deburr the inside edge. A flap wheel could probably used to deburr the threads and may work for the inside edge as well.


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## furnacefighter15 (Jun 21, 2020)

What part is sharp? Just the edge where the thread starts? 

A picture would help. Im a pipefitter by trade.

If its just where the thread starts on the inside edge, then the reamer would fix that. 

If its sharp cause the steel is so thin that its a knife edge, then you can trim off that edge with a metal cutting blade in a chop saw. Just take a blade kerf worth. Then check and see if it will still thread in to where is needed.

The other option would be to leave the pipe alone, and run the wiring inside of a loom, or make your own loom by wrapping the wire set in electrical tape. Sort of like how car MFGs do it.

Or get SO cord for the wires as it has several layers of sheathing that wont be bothered. SO cord is similar to extension cord, but more heavy duty - the big box stores have it in the cut to length wiring area.

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## furnacefighter15 (Jun 21, 2020)

SO cord

https://www.homedepot.com/p/Southwi...e-Portable-Power-SOOW-Cord-55809999/204632918

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## furnacefighter15 (Jun 21, 2020)

The style in the link that is pen shaped would work for deburing. Its made for copper, but will work with steel with a little effort.https://www.homedepot.com/p/Husky-1...mer-and-Deburring-Tool-410-248-0111/308500885

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## Dylan JC Buffum (Jun 9, 2019)

Thanks for the suggestions. Those flap wheels look super cheap on Amazon, so I’ll order some. I might also try the reamer suggested by furnacefighter.

The whole spiral is razor sharp. Some even have small shards of metal slivers still attached.

I wonder if spraying some wd-40 and fine sand into a female coupling and just running the nipples in and out a few times would help?

There are enough of them that I don’t want to spend 10+ minutes on each.


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## GaryCK (Mar 25, 2018)

Potentially dumb question, Dylan. Wouldn't the threads on the outside of the pipe interface with the threads on the inside of the fittings, eliminating access for the wiring to both of them? If so, your problem is reduced considerably.


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## furnacefighter15 (Jun 21, 2020)

GaryCK said:


> Potentially dumb question, Dylan. Wouldn't the threads on the outside of the pipe interface with the threads on the inside of the fittings, eliminating access for the wiring to both of them? If so, your problem is reduced considerably.


This is correct.

I would only be concerned with the inner side of the pipe nipples. The outer threads will mate with the female threads on the fittings.



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## Dylan JC Buffum (Jun 9, 2019)

GaryCK said:


> Potentially dumb question, Dylan. Wouldn't the threads on the outside of the pipe interface with the threads on the inside of the fittings, eliminating access for the wiring to both of them? If so, your problem is reduced considerably.


Not dumb, and correct. But some of the male thread will be exposed because pipe thread is tapered. While it’s not likely to be handled a lot when finished, it’s still not ideal to have razors affixed to the outside of the fixture.


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## woodnthings (Jan 24, 2009)

*The reamer will be too expensive ......*

https://www.amazon.com/Alfa-Tools-M...p/B00DYFQC5U/ref=psdc_256298011_t2_B00DYFQEDU

A one time job means finding a cheaper solution to deburring the sharp edes. Something like these will fit in a hand held drill:
https://www.harborfreight.com/5-piece-1-4-quarter-inch-shank-mounted-stone-set-94992.html


Cheap enough to get several sets to replace the ones that get worn down......


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