Topic: Chasing threads

[The Gurg]

10mm x 1.25 bolts for the shock mounts on a cb750 K5. Acorn nuts aren’t threading on. There is a bump on the third thread. This will be my first time chasing threads. With the engine mounted, chasing thread on the frame makes me a little nervous. Looking for any tips. Planning on picking up a hex die tomorrow. Going to use bel ray to lube the die unless someone objects.

[HondaMan]

Do you have some needle files? A small triangular file should be able to smooth the edges of that bump down to let the nut thread back on.

[754]

Yeah what Hondaman said.  Triangular is the right profile, if you have a very small  file with a oval cross section, use it first to remove a lot of it. Probably won't need a die , but don't force the nut.. and a few drops of oil is good.

[pjlogue]

If you do use a die, be sure the thread pitch match the stud.  I seem to recall the thread pitch being hard to find when I was restoring my '76 750 and finding the nuts was difficult.  Hand start the die as they are easily cross threaded because of the taper on the die.  Use oil as well.

-P.

[jlh3rd]

i use this tool called threadmate. It works on any pitch thread.....Its about 1/2 inch thick so a male stud needs to be long enough. Its saved many bolts.

[madmtnmotors]

I prefer something like this when repairing threads:

https://www.amazon.com/Lang-972-Fractional-Metric-Restorer/dp/B000P6UNHE

These are less aggressive than actual taps and dies and can even push damaged threads back into shape (especially threads in aluminum) instead of cutting everything out of the way. The thread files are nice too but they do require a little practice, patience, and a steady hand doesn't hurt either. I got so much use out of my 40 piece set I bought another set with 48 pieces. You may need to address the threads inside the acorn nut as well.

i use this tool called threadmate. It works on any pitch thread.....Its about 1/2 inch thick so a male stud needs to be long enough. Its saved many bolts.

Ye-ow! That is a little steeper than I imagined:

https://www.amazon.com/NES-Thread-Repair-NES01044-ThreadMate/dp/B003YIB38I

although I'm not afraid to spend money on tools... 

[jlh3rd]

I prefer something like this when repairing threads:

https://www.amazon.com/Lang-972-Fractional-Metric-Restorer/dp/B000P6UNHE

These are less aggressive than actual taps and dies and can even push damaged threads back into shape (especially threads in aluminum) instead of cutting everything out of the way. The thread files are nice too but they do require a little practice, patience, and a steady hand doesn't hurt either. I got so much use out of my 40 piece set I bought another set with 48 pieces. You may need to address the threads inside the acorn nut as well.

i use this tool called threadmate. It works on any pitch thread.....Its about 1/2 inch thick so a male stud needs to be long enough. Its saved many bolts.

Ye-ow! That is a little steeper than I imagined:

https://www.amazon.com/NES-Thread-Repair-NES01044-ThreadMate/dp/B003YIB38I

although I'm not afraid to spend money on tools... 

no,no...that's not it....look at the pic....i bought that little tool years ago. Actually, purchased from Griots garage but i'm assuming it's out there in general.........

[jlh3rd]

here's something similar.......still kinda expensive......but, has saved me countless times....

[madmtnmotors]

no,no...that's not it...

I believe it is. The tool I linked to has both tools, one for the external thread (like yours) and also the tool for repairing internal threads. 

[jlh3rd]

no, here is exactly what i purchased years ago....just this single tool.....no internal.

[BenelliSEI]

Another option is a thread chaser file. Most are  four sided, and each end is different. They come in metric and standard pitches, so each file has 8 different thread sizes. Just lay the correct one in the threads and use a rolling motion as you file......  I’ll add a photo. Next time I am in the shop. Saved many a bolt and stud with my set!

Just added “Amazon Photo”. Note the metric file at the bottom (like the one I use) has 8 different cutting faces (4 at each end). So one tool is all you need for your metric bike. Lifesaver.

[jlh3rd]

10mm x 1.25 bolts for the shock mounts on a cb750 K5. Acorn nuts aren’t threading on. There is a bump on the third thread. This will be my first time chasing threads. With the engine mounted, chasing thread on the frame makes me a little nervous. Looking for any tips. Planning on picking up a hex die tomorrow. Going to use bel ray to lube the die unless someone objects.

since you say this is your first time, the problem i'd have recommending a die is that if you don't get the die started correctly, which might prove difficult for a first timer, and because the threads are screwed up at the tip......you might start cutting threads crooked....because that's what a die is for...cutting threads.
     Tools that let you line it up with the undamaged threads as a guide, will enable you to correctly repair the damaged threads.....that's what benelli's tool will do, the one i use also.........triangle files i've used also , but space may limit access.........
     yes, a die can work.........i've done it........but i've been doing this stuff for decades..........i really like that  tool i have but it only goes to 1/2 inch......
     

[grcamna2]

What madmtnmotors has are actual "thread chasers",they remove the least amount of metal while actually restoring the existing threads.A regular die or tap will cut more metal off and cause the threads to be more loose w/ more of a chance of stripping-out the threads later.. Buy a set of "thread chasers" rather than a tap or die.I especially like running the 6mm male chaser down into cast aluminum threads,makes a very smooth threaded hole with those small ones w/o reaming-out the original factory threads like a 6mm regular tap used to do.,cleans-out build-up too.
I purchased these for small $ from a place in Ma. called metricscrewandtool.com,I bought these from them on Ebay but they also have a site you can purchase Many metric bolts,nuts,screws and tools.

[The Gurg]

Bought a thread chaser file. Seeing that BennelliSEI suggested it. Going to give that a try when I get it on Monday. Everyone mentions a small triangle file. Is this file small enough? Should I give it a try first?

Was watching a video about using the hex die nut and does seem a little challenging to get it started if the issue is at the start of the threads. So I’m going to hold off with that for now like jih3rd suggests.

[PeWe]

Needle file set of 5-6 different shapes is useful.
Tringular shape and other to repair threads.
A flat one when gapping piston rings. File fastened in a vise, clamp ring ends around file and move inwards.

[jlh3rd]

Bought a thread chaser file. Seeing that BennelliSEI suggested it. Going to give that a try when I get it on Monday. Everyone mentions a small triangle file. Is this file small enough? Should I give it a try first?

Was watching a video about using the hex die nut and does seem a little challenging to get it started if the issue is at the start of the threads. So I’m going to hold off with that for now like jih3rd suggests.

your trying to repair a threaded, non removable part of your bike. If you screw it up, it becomes harder to fix, perhaps not fixable. I don't think it's replaceable, right?
     So that thread chaser you have is not what benelli showed you. It's different. Actually, i don't see how yours would work. Look at his pic, that tool has specific, matched threads to fit into the good threads, line it up correctly, and dress the damaged threads.
Also, yeah, i guess your file would work, but look at your edge compared to mine (pic). Mine is sharper and lets me get into the groove without grinding away at the sides. Yours looks pretty worn.....but i'm not there to really see...
Just offering opinion, as you've asked.....i'm treating it like it's my bike though...

.

[grcamna2]

Bought a thread chaser file. Seeing that BennelliSEI suggested it. Going to give that a try when I get it on Monday. Everyone mentions a small triangle file. Is this file small enough? Should I give it a try first?

Was watching a video about using the hex die nut and does seem a little challenging to get it started if the issue is at the start of the threads. So I’m going to hold off with that for now like jih3rd suggests.

The needle file set is a good idea also:the smaller the file,the better.

[The Gurg]

The picture of the file is just the one I have on hand. Sounds like I shouldn’t use it. This is the one that is coming Monday:

https://www.fastenal.com/products/details/0817944

Several suggestions to get a needle file set. Going to pick one up to have around. Surprised at how cheap a lot of these are. Harbor Freight has a set for $3. Anyone have any recommendations.

[The Gurg]

Would get a buckingham thread chaser or thread mate or something similar. Seems a bit pricey for this repair, but maybe not? I could definitely be talked into it.

[jlh3rd]

your good then....needle files, great......harbor freight?...that's a toss up. I've had good/bad experiences. I've stayed away from their wrenches, sockets...pry bars have bent fairly easy....that kind of stuff......files? eh, probably work for ya a few times, and be ok in this case....i have a list....let others chime in....

hard to go wrong for $3...can't screw anything up..

[jlh3rd]

Would get a buckingham thread chaser or thread mate or something similar. Seems a bit pricey for this repair, but maybe not? I could definitely be talked into it.

well,  $34 bucks....

[The Gurg]

Oh, it is only $34! Says metric and 10mm is in the range so that looks right. I went ahead and bought it. Arrives Sunday.

So now the question is which tool to use first...

I’ll probably practice on some old rusty 10mmx1.25 bolts. Mash the threads with some channel locks or a hammer.

[BenelliSEI]

WAIT for the one from FASTENAL. That seems a hell of a price, but I bought my pair 40 years ago.....
One is metric, one’s imperial. As I explained earlier, with the 8 X filing faces, you get 8 different pitches on one file..... it has the advantage that you can repair any bolt or stud size, and do it in place. It will last you forever.

[Prospect]

This is what I use. It's essential for dealing with our old steeds.  Used it today on several threads.  It gives a euphoric sense of satisfaction when a bolt goes in like new.

[madmtnmotors]

I have used small files with good results. Take your time, do a little at a time, and check frequently. I would suggest a different nut of the same size/pitch as the acorn nut unless you have been able to verify that the threads in the acorn nut are not similarly damaged. The same suggestion applies to the use of an actual thread file as well.

[The Gurg]

Madmtnmotors-
Good advice on the acorn nut. Both acorns were stripped. Have some nuts I picked up from the specialty bolt store downtown when I picked up the die that I can use until I get the replacements oem acorns coming from partzilla. I’ll follow your advice and use the nuts in the process of fixing the threads.

[HondaMan]

Oh, it is only $34! Says metric and 10mm is in the range so that looks right. I went ahead and bought it. Arrives Sunday.

So now the question is which tool to use first...

I’ll probably practice on some old rusty 10mmx1.25 bolts. Mash the threads with some channel locks or a hammer.

Excellent plan!

[The Gurg]

Thanks all!!! Would have ruined these shock mounts without all your help!

Update: decided to start with the thread chasing file. Practiced for 15 minutes on a old 10x1.25 bolt that I purposely mashed the threads on, then I took my time filing the shock mount (using a circular motion, credit BenelliSEI), finally was able to partially thread on a nut, so oiled everything and ran the hex die down the threads. When I thread on a nut, the threads feel like the other shock mount.

[754]

 Way to go, it looks good. .
 You have a remarkably good attitude  to making a proper effort to repair  it.
 Unlike some on here that are offended, when it gets suggested they buy a pitch gauge to measure their threads...

[grcamna2]

That looks good,did you purchase a thread chaser hex die ?

[bryanj]

Well done mate, all is possible with care and time

[The Gurg]

Thanks for the affirmation guys!

Gramna2-
I had purchased the hex die before posting, mentioned it in the initial post. Everyone (wisely) talked me out of starting with the die.

[madmtnmotors]

Well done. Patience usually wins in these matters. I used to get upset over broken/damaged bolts/threads, but now when damaged fasteners rear their ugly head my first thought is to start formulating a plan as to how best to approach the repair. 

[754]

 Got a funny story. .
 A guy from a neighbouring shop brought in a shaft with a damaged thread.. so I fixed it with a triangle  file and a thread file ... but in the lathe.... he got sort of quiet as he watched.. and then he said I got one of those..did not know what it was for !
 I said well I have charge you a bit..it was like 8 bux or so.... But I added now you know what  to do next time., I said how did you end up with one, big knowing what it was for... he said he got a few tools from his Grandpa..

[The Gurg]

Haha I can relate. Caught the end of an estate sale one time and they hadn’t sold much. I asked how much for all the tools and hardware. And they let me have everything for $100, filled up my trunk and every bit of the cabin of my car. The guy had a window dressing company before he retired, so there is a lot of random tools and window hardware. I wound up pitching half of it, but what I’ve kept has saved me many times my $100. I’ve figured out what a lot of stuff is over the years. But every once in a while come across something that stumps me. Both files I had pictures of in this thread were from that window dresser.

[754]

  Post a what is it thread when you are stumped.l

[BenelliSEI]

I may have mentioned this before, but my thread chasers and a set of Greenlee Knock Out Punches came to me the same way. I used to “borrow” them from the mechanic at a Texaco Service Station. It was at the end of the block, when I was a kid. Bill repaired the end of an axle on my mini bike. I pumped gas at the station, the summers I was 14 and 15 years old ($1.00/hour + tips). When Bill retired a few years later he said: “you use these more than me” and gave them to me. I used the punches for putting holes in alloy panels in my race car...... he was a cool guy and I still enjoy those tools. 50+ years later.....