Tap and die vs retread kits.

bobcatdan · Feb 11, 2012

I havn't seen any direct comprassions to tap and dies vs retreaders other then don't try to cut new treads with a rethreader. I have an SO tap and die set and over 90% of the time just use it clean trheads. I do very little cutting of new new threads. Is there a real rason to use a retread tap or die over a real tap or die. I don't care if I am wearing out my set, I can replace it free. I just want know if there is someting about using a rethreader to clean threads that is better. I have a feeling I'm spilting hairs here, but there always seem to be a real intrest in rethread kits like the ones from kastar and I'm just wondering why? Thanks.

ssblood · Feb 11, 2012

Taps will sometimes cut part of the thread out. Rethread kiss only straighten the threads.

Packard V8 · Feb 11, 2012

The engine rebuilder shops I go into use old worn taps on an air drill to clean threads.

One main advantage of the rethreading kit is they're easier to run in and out with a socket and speeder.

On bolts, the rethreading dies start easier than a cutting die and again can be used with a socket or wrench instead of requiring a die stock.

jack vines

ol'Red · Feb 11, 2012

Also a taps dont reach the desired diameter until maybe 1/4 of the way down the bit so you cant get those threads in the bottom.

Skin · Feb 11, 2012

bobcatdan said:
I havn't seen any direct comprassions to tap and dies vs retreaders other then don't try to cut new treads with a rethreader. I have an SO tap and die set and over 90% of the time just use it clean trheads. I do very little cutting of new new threads. Is there a real rason to use a retread tap or die over a real tap or die. I don't care if I am wearing out my set, I can replace it free. I just want know if there is someting about using a rethreader to clean threads that is better. I have a feeling I'm spilting hairs here, but there always seem to be a real intrest in rethread kits like the ones from kastar and I'm just wondering why? Thanks.

The real benefit of the rethreader kits is they come in common bolt sizes and are much smaller as you're meant to use them with just a socket where as dies require a die wrench [or 1" socket if you have a hex variety]. In many under the hood automotive applications you usually dont have enough space to spin a die wrench.

ptschram · Feb 11, 2012

ol'Red said:
Also a taps dont reach the desired diameter until maybe 1/4 of the way down the bit so you cant get those threads in the bottom.

Sounds like you haven't heard of plug and bottoming taps.

I have both thread cutting tools and rethreading tools. There are times I prefer to use one or the other.If I could only have one, I'd have thread-cutting tools.

Outlawmws · Feb 11, 2012

ol'Red said:
Also a taps dont reach the desired diameter until maybe 1/4 of the way down the bit so you cant get those threads in the bottom.

That depends on whether you are using a starter tap, a plug tap, or a bottoming tap...

Edit: didn't quire make it to the bottom post...

Trucky · Feb 11, 2012

Most of the cheap tap kits don't come with plug and bottom taps. And people don't care to spend the money for them, if they even know they exist, so I don't really blame him for not knowing. Obviously anyone who uses them all the time or works at a shop that does metalworking would know, but not the average joe.

As far as rethreads or tap/dies go, it doesn't really matter too much. What does matter, is that you have the right size one to even attempt the job. If you don't, you're SOL :lol:

SINISTER · Feb 11, 2012

A good re-thread kit is also much cheaper than a good tap&die kit.

If you had no real use for a air ratchet would you go out and buy one because you have to turn down a 2 ft long fine thread bolt one time? No, or at least I hope not. If you had to turn that same bolt everyday you might just get one.

If you do a lot of fabrication and need to cut your own threads everyday you most likely will have a tap and die set, if you have to clean a thread or two here and there it doesn't make much sense to have a re-thread kit as well.

I work in a shop and own a thread restore set. Got is from snap-on for I thing 75$ all it is, is a re-branded Kastar. I use it on a daily basis to clean lug studs, nuts, rusty exhaust manifold studs and nuts ect. the list goes on. I have no real use for a tap&die kit, when I need one I go buy one and add it to my collection.

USMCdodge · Feb 11, 2012

new guy question- so rethread kits just straighten out existing threads and tap and die sets cut new threads from smooth holes?

ptschram · Feb 11, 2012

USMCdodge said:
new guy question- so rethread kits just straighten out existing threads and tap and die sets cut new threads from smooth holes?

Correct.

(crotchety old man comment follows)This thread illustrates the danger of doing away with shop classes in junior high and high school.(crotchety old man comment closed)

USMCdodge · Feb 11, 2012

Im teaching myself. with a lot of help from you guys. working in a metal fab shop helps too. Im hungry for knowledge.

greasemonkey44 · Feb 11, 2012

hmmm a complicated proposal
i use mostly rethreaders at work; they are built to be driven with sockets and center themselves into the holes or over the bolt
i used to use tap and die set for cleaning out thread holes; they do a great job, but usually try to cross the threads in the hole
rethreaders dont; they just shove the thread materiel back into place
tldr for my job id rather have a set of rethreaders; they are fast, efficient and cheap

OccupantRJ · Feb 11, 2012

ol'Red said:
Also a taps dont reach the desired diameter until maybe 1/4 of the way down the bit so you cant get those threads in the bottom.

That's why bottom taps are made.

OccupantRJ · Feb 11, 2012

USMCdodge said:
Im teaching myself. with a lot of help from you guys. working in a metal fab shop helps too. Im hungry for knowledge.

Here you go. Enjoy.

http://en.wikipedia.org/wiki/Tap_and_die

OccupantRJ · Feb 11, 2012

There are also thread forming taps available which have no cutting edges for use in machine tools. They are called thread forming taps, and are simply rotationally rammed into the proper size hole to form threads. :willy_nil

Metal is more elastic than most people seem to realize.

Danglerb · Feb 11, 2012

Taps and dies cut on every pass, each time you use them the fit gets looser.

amolaver · Feb 13, 2012

OccupantRJ said:
There are also thread forming taps available which have no cutting edges for use in machine tools. They are called thread forming taps, and are simply rotationally rammed into the proper size hole to form threads. Metal is more elastic than most people seem to realize.

not only that, but formed threads - rather than cut - are MUCH stronger.

ahm

woody 73 · Feb 13, 2012

ptschram said:
Correct.

(crotchety old man comment follows)This thread illustrates the danger of doing away with shop classes in junior high and high school.(crotchety old man comment closed)

Old Geezer comment to follow: You might be on to something but I wish I had computer training when I was young it sure would help me today,but then I only had a slide rule! old Geezer commment closed. :lol:

Tap and die vs retread kits.

bobcatdan

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ssblood

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Packard V8

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ol'Red

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Skin

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ptschram

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Outlawmws

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