chasing threads

[southpier]

neophyte fabricator - chased some banged up threads with the correct sized die and ended up double threading the bolt! did i just get the die to pick the wrong starting point/ uneven, or is there a difference in a rethreading die & a threading die?

thanks

 

[ghnl]

Yes, re-threading taps & dies are much less likely to cut new threads. They follow the old threads and clean them up.

http://buy1.snapon.com/catalog/item.asp?item_ID=71303&group_ID=1146

 

[rsanter]

they are not the same
both will work, however a regular die will remove material from the damaged area and the rethread die will try to force the material back where it belongs.
are you sure you were using the correct threaded die? are you sure it was not a metric (or SAE) and was just similar in size and thread as to what you were needing?

bob

 

[Big_John]

While the rethreading dies work better, I have used a regular die to repair threads by inverting the die. The first few threads of the die are tapered to start cutting the thread and by inverting it the die does not tend to cut its own threads.

Another way is to use a thread file to dress up the threads. Its hard to get in trouble with a thread file.

 

[southpier]

so it sounds like i've been lucky to not have had this happen before.

and now i can get the "right tool for the job"

thanks for the help

 

[Uncle Buck]

so it sounds like i've been lucky to not have had this happen before.

and now i can get the "right tool for the job"

thanks for the help

Either tool will do what you were trying to accomplish, neither tool is actually incorrect for the task. Please do not take this as wrong, but it does not sound like you knew how to use the tool. I suspect you were not using a die of the same thread size as the bolt you were chasing.

I do not have any re-threading dies, and I am sure many others do not as well. If you know what you are doing, really you can get along just fine without re threading dies.

The reason I posted this is that it does rub me the wrong way for guys to be left with the impression that what you described is a routine occurrence, or more like than not event when using a conventional tap/die set as opposed to a re thread set, which put blunt, is simply not true. If you select and use the right size tap or die for the job what you described would not happen. I suspect you used a fine thread die to chase a coarse threaded bolt, which would look just as you described if you did that. Good luck, I hope I did not offend, that was not my intention.

 

[Jey]

I've always use die's to chase threads, mostly because i don't have thread chasers.

The problem is when the first thread is off, you start cross cutting new threads. This happens from time to time. also, if you're not square when you start the die.

 

[Joe69]

Ever since I bought my set of rethreaders, I hardly ever use my taps and dies anymore. Besides, I'm not dulling my tap and dies chasing existing threads.

Joe

 

[Doozer75]

southpier just used a fine thread die on a course thread bolt. You can not double thread a bolt. If you had a lathe and you wanted to make double lead threads, yes you can do that, but I think he just used the wrong die.

--Doozer

 

[nissan_crawler]

southpier just used a fine thread die on a course thread bolt. You can not double thread a bolt. If you had a lathe and you wanted to make double lead threads, yes you can do that, but I think he just used the wrong die.

--Doozer

Yes, yes you can. I've seen threads cut right into the peak of threads all the way down the fastener from trying to run a die down it. I've never had trouble doing it, but yes, you very much can double thread it.

 

[t. jones]

what the guy on fire said, threadfile

 

[ProGun3400]

http://www.sears.com/shc/s/p_10153_12605_00942275000P

 

[Doozer75]

"Yes, yes you can. I've seen threads cut right into the peak of threads all the way down the fastener from trying to run a die down it."

Wow, Stupid really is the strongest force in the universe. Move over black holes!
I stand corrected.
--Doozer

 

[Vinko]

Is that SO/Crafty set made out of low-carbon steel? I wonder if it'd chase grade 5 and grade 8 threads?

 

[southpier]

well ... i did end up buying a set of thread files, but i certainly could have been guilty of any possible means to mess up on the original bolt. i have relieved myself of a great deal of pressure by not having to do everything perfectly. so i just learn as i go along . . .


thanks