Tap and die sizes for rebuild

pwizl · Oct 31, 2013

In the process of rebuilding a motor and I want to chase all the threads of the bolt holes and studs. Does anyone have or know of a list of tap and die sizes and the corresponding bolts and studs they go with? For instance...head bolts are x mm by x pitch etc.

RatyXS · Oct 31, 2013

http://www.shender4.com/thread_chart.htm

wherearewe · Oct 31, 2013

If you have even an average tap and die set, you should have one of those little thread checker tools. Always a good idea to keep the old hardware so you can check it against that. Being metric the majority of it can be done with a fairly basic set. You can always do specific searches too if you encounter a weird one.

A list would be a nice reference tool. Someone should make one... :wink2:

pwizl · Oct 31, 2013

wherearewe said:
If you have even an average tap and die set, you should have one of those little thread checker tools. Always a good idea to keep the old hardware so you can check it against that. Being metric the majority of it can be done with a fairly basic set. You can always do specific searches too if you encounter a weird one.

A list would be a nice reference tool. Someone should make one...

I was just going to do that, use the existing hardware, just hoping there was a list already so I could just whip thru it. I'm kinda lazy like that :laugh:

As I go I'll keep track and make up a list.

TwoManyXS1Bs · Oct 31, 2013

Hoo-boy.... I'm gonna throw a wrench in here and ruffle some feathers. Be advised that many of the fasteners and threaded holes use a non-consumer 'Class of Fit'. Look at the attached pic (thanx RD51), and the aluminum chips collecting below.

The tap, while of the correct nominal size, is larger than the closer 'class of fit' of the factory tapped holes. The resulting hole may not hold to the original torque specs.

Class of Fit explaination: http://www.katonet.com/article/science.html

This can get into a very exhaustive research project, trying to find the original specs for all the fasteners, including cut and roll-formed threads. To learn more, try googling 'metric thread class of fit'.

Best I can say for the moment is: If at all possible, try to cleanout the threads without cutting the aluminum.

pwizl · Oct 31, 2013

TwoManyXS1Bs said:
Hoo-boy.... I'm gonna throw a wrench in here and ruffle some feathers. Be advised that many of the fasteners and threaded holes use a non-consumer 'Class of Fit'. Look at the attached pic (thanx RD51), and the aluminum chips collecting below. The tap, while of the correct nominal size, is larger than the closer 'class of fit' of the factory tapped holes. The resulting hole may not hold to the original torque specs.

Class of Fit explaination: http://www.katonet.com/article/science.html

This can get into a very exhaustive research project, trying to find the original specs for all the fasteners, including cut and roll-formed threads. To learn more, try googling 'metric thread class of fit'.

Best I can say for the moment is: If at all possible, try to cleanout the threads without cutting the aluminum.

Thank you sir, I will definetly keep an eye on that

XSLeo · Oct 31, 2013

I have a craftsman 40 piece metric tap and die set. I don't really use many of them. A 15 or 20 piece set would do as well.
I don't use them on every bolt. Just the ones that really need it. A bit of rust or crud gets brushed out with a wire brush. This usually gets them clean enough.
Leo

Street Tracker · Nov 4, 2013

I have a tap and die set and a thread chaser set, the thread chaser set is what you want to use it will bottom out being blunt ended and does not really cut the threads only the bogeyed up ones.

TwoManyXS1Bs · Nov 4, 2013

Is that thread chaser set 2-flute or 4-flute, straight or spiraled?

Street Tracker · Nov 4, 2013

I would have to go check but I am betting from memory 4 flute, and looks like straight from what I recall

DozerDan · Nov 5, 2013

Wire wheel on a bench grinder and some good safety glasses work great for bolts.

For a 'good' nut a same sized bolt with reliefs cut in it will chase out crap.

A good tap and die (notice the word good) will work great for both, but if you buy cheap you get what you pay for, and it will cost you more to have someone remove a broken 4 flute from your head/block than its worth.

TwoJugs · Nov 6, 2013

"chasing" the threads is not as critical as cutting new ones. I have a cheap import set that is pretty complete with taps and dies. Both starting and bottom taps. I use it to clean up hardware or help me to find out what size I am working with. When I am cutting threads I use my USA tools. Mostly Vermont Tool brand. I can get them at my local Ace harware by the piece. I do not use import economy taps to cut threads. They snap off easy and can be a real challenge to remove.

Yes I also have pitch gages and fine stainless and brass wire wheels to handle the light work.

Tap and die sizes for rebuild

pwizl

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RatyXS

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wherearewe

Rub on Ya Titties

pwizl

XS650 Addict

TwoManyXS1Bs

BBQ Hunter

pwizl

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XSLeo

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Street Tracker

Dirt Track Mentality

TwoManyXS1Bs

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Street Tracker

Dirt Track Mentality

DozerDan

XS650 Enthusiast

TwoJugs

Excess XS

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