# Rethreading taps and files



## Chicken lights (Jun 30, 2019)

Anybody else have a set of these? 

I’ve never used the files at the bottom of the case. To be honest I’m not even sure how to use them. 

The rethreading taps and dies are a staple in my shop, they get used quite a bit. I’ve always been told to use them over a regular tap and die set because you run the risk of crossthreading a tap/die and cutting new threads instead of chasing the old ones 

Also I’ve been told a tap/die can remove extra material weakening what you’re working with instead of just cleaning it up.


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## Chicken lights (Jun 30, 2019)

So, for example, I had these two studs the brackets mount to. I only had one bracket originally, the other stud had a hard plastic covering on it. I pulled the old bracket off, pulled the hard covering off the other one, then sprayed both with penetrating fluid. I started the thread chaser by hand then used a small 1/4” ratchet to wind the chaser up the threads. Backed it off, wiped both off, added anti-seize and bolted the brackets on. 

I don’t like “forcing” stuff to go together. I use a 1/4” ratchet for most of my work. Don’t get me wrong I’ll pull out the big tools if need be. But I find the smaller tools give you better “feel” when assembling things.


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## Chicken lights (Jun 30, 2019)

Also, I quite like these for finding out the correct bolt size and pitch. 

The last time I did something on the motor I pulled out a 7/16 coarse bolt. Threading a chaser in felt loose and sloppy. Knowing my motor should probably be metric I grabbed an M12 chaser and threaded that in, instead. It felt like the right size so I scrounged an M12 bolt and used that instead. 

For instance on those studs I ordered in a new stud, used the thread chaser to find the right size, then ordered some nuts so I could have everything ahead of time. 

I was really nervous to tackle this on a long weekend but fingers crossed it’s apart and back together and I’m not short any parts


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## Tom O (Jun 30, 2019)

The files have a number stamped on them showing the tpi in metric or imperial one file is imperial the other is metric used in the thread for removing dings and such.


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## Janger (Jun 30, 2019)

Chicken lights said:


> View attachment 5465
> Anybody else have a set of these?
> 
> I’ve never used the files at the bottom of the case. To be honest I’m not even sure how to use them.
> ...



Post a Link to similar set pls?


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## Chicken lights (Jun 30, 2019)

Janger said:


> Post a Link to similar set pls?


https://store.snapon.com/U-S-Metric...ster-Rethreading-Tap-and-Die-Set-P641094.aspx

That takes you to the Snap On USA site but I have the same kit. Only difference is pricing


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## Chicken lights (Jun 30, 2019)

Tom O said:


> The files have a number stamped on them showing the tpi in metric or imperial one file is imperial the other is metric used in the thread for removing dings and such.


Interesting. So kind of like a wire brush you would “file” the ding out of exposed threads? 

I can’t think of where I’d use them, that i can’t use the tap or die chaser

Which is why they’re unused.


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## historicalarms (Jul 1, 2019)

When grinding screws to shorten them for a specific usage these "files" can be used to re-form the starting tread to accept a nut easily.


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## Chicken lights (Jul 1, 2019)

historicalarms said:


> When grinding screws to shorten them for a specific usage these "files" can be used to re-form the starting tread to accept a nut easily.


I was always taught to thread on a nut first, then cut off the bolt. That way unthreading the nut cleans up the threads 

The last bolt I had to shorten was an M12 that I actually used the thread chaser instead of a nut. I didn’t have any M12 nuts so I did what I had to do. It wasn’t my first choice but it worked


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## CalgaryPT (Jul 1, 2019)

I don't do much thread chasing on internal threads, and when I do I use taps. But for external threads, I think the NES tools (made in Israel) are great quality. I have the set with both the small chaser and the large one, and use them both. The only place they don't work well is on damaged threads at the end of the rod/bolt. For these the thread files @Chicken lights show are best; you just repeatedly run them across the threads. 

I had a blonde moment with mine years ago when I got them from Princess Auto. I needed to file a 16TPI thread but the closest one on the file was 18TPI. I was mad thinking now I need to go back and buy another set.... Turns out you remove the red vinyl handles to access the other sizes (just like in @Chicken lights pic.)

OK...maybe beer was involved. But damn it...there were no instructions GRRRRRR.


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## Janger (Jul 1, 2019)

Those are cool


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## Chicken lights (Jul 1, 2019)

CalgaryPT said:


> I don't do much thread chasing on internal threads, and when I do I use taps. But for external threads, I think the NES tools (made in Israel) are great quality. I have the set with both the small chaser and the large one, and use them both. The only place they don't work well is on damaged threads at the end of the rod/bolt. For these the thread files @Chicken lights show are best; you just repeatedly run them across the threads.
> 
> I had a blonde moment with mine years ago when I got them from Princess Auto. I needed to file a 16TPI thread but the closest one on the file was 18TPI. I was mad thinking now I need to go back and buy another set.... Turns out you remove the red vinyl handles to access the other sizes (just like in @Chicken lights pic.)
> 
> ...


Out of curiosity- what do you think of the difference between using a tap versus a thread chaser?

Me, personally, I prefer using thread chasers. I think a tap or die is too aggressive. I’m not trying to cut threads I’m trying to clean up what I’m working on. 

I don’t think you using taps to chase threads is a bad thing, that’s the whole reason for the discussion is to bounce ideas off different members


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## CalgaryPT (Jul 1, 2019)

Good question, I don't really know. If I had to guess I'd say you're right: the internal thread chaser is less aggressive ( 



 ). I suppose if the threads are *really* damaged, the chaser would only focus on the damaged areas, whereas the tap might wander when it encounters these. That could either make it break off, or cut into the existing threads and damage them. I guess this falls under the aggressive description you mention.

You know that feeling you get with a tap when it is cutting just right and you've figured out how much pressure is needed to cut well and when to reverse? I never get that when using a tap to chase threads: it's just a nasty bump against the damaged area and a prayer that it won't break as you push through. I'll bet the forces on the tap are concentrated on one area rather than spread out across the tap, hence the likelihood of it breaking.

I'm not adverse to internal thread chasers, but the NES set was pricey if I recall. I needed it mostly for externals and so compromised by not getting the more expensive set with internal chasers. A lot of the internal ones I have fixed over the years by plug welding and then re-tapping. If I were doing internals more often then I'd consider buying an internal set.

BUT if I do break a tap in there I want to have this guy help me:


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## Chicken lights (Jul 1, 2019)

CalgaryPT said:


> Good question, I don't really know. If I had to guess I'd say you're right: the internal thread chaser is less aggressive (
> 
> 
> 
> ...


Fascinating video. That guy is going to be, sadly, a lost resource for younger generations 

Yes, I agree with you on the “feel”. That’s why I generally use 1/4” drive tools, I can “feel” when things are good or bad 

Do you know what I mean when I say an “EZ out”? Generic term for a bolt extractor? Anyway same thing like you’re saying, not much difference between when things are going well and breaking one

Again out of curiosity what kind of money is the NES tool line? I’m thinking my snap on set was $200, ball park


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## CalgaryPT (Jul 1, 2019)

My set is on sale at Amazon.ca for $215 now.

https://www.amazon.ca/External-Thre...thread+repair&qid=1562034689&s=gateway&sr=8-4

But when I got it, it was much more expensive. I was working on a lot of threaded rod projects at the time, so I hope I justified it.


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## Tom O (Jul 2, 2019)

i just bought a 6 set series of home shop machinist (1995) that shows how to build a edm by Robert P langlois.


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## CalgaryPT (Jul 2, 2019)

Tom O said:


> i just bought a 6 set series of home shop machinist (1995) that shows how to build a edm by Robert P langlois.


Fascinating process  Are you going to build one?


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## Tom O (Jul 2, 2019)

I’d like to but will have to see how it goes I’ve never made a board up before but I believe I have everything to make one and my electrical skills are basic I’ll price out the components.


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