Various thread pitch’s needed

[busmania]

Yes team, I have a thread pitch gauge, I have the tap and die set, I know how to use it, I've used it for years on the metric system (old vw buses...ive chased dozens of threads but I always knew the size and thread count) etc. I just don't trust my ability to use the thread pitch gauge on unknown pitches therefore this thread is to verify thread pitches before I screw up another one that might actually matter (the one I screwed up was a test bolt but it didn't go well....not cause I dont know how to use a thread/die set but because I mis measured with the tool now I am second guessing myself. Thanks!

Again, the purpose of this thread was just to verify pitches of various threads before I chase them with the wrong die. My hope is to come up with a list of various thread pitch/sizes and aggregate them in this thread for future google searchers like myself. I don't need any help with the tooling. Just trying to NOT screw up more threads.

[busmania]

so anyway, back to the intent of the thread, I have two numbers so far. keep em coming!

Rear axle nut - 5/8 x 18
Steering column nut - 5/8-18. Standard 5/8 UNF thread.


how about fender bolts? I have a lot of those that need to be chased! what about cylinder head stud holes? gonna have to do those too.

[nickthebandit]

FYI, a lot of bolts that Ford used were non-standard sizes. For instance, the thread on the end of early ford spindles is 11 / 16"- 18. That is where the hinged tool comes into play. The head stud holes are a tapered fit. Do not chase those holes with standard taps, you will have leaks.

[frnkeore]

Regarding the stud holes for the head, they are tapped to .0025 under the nominal pitch diameter and the drilled hole is to be between .349 and .353.

The proper tap will be 7/16x14 H-5, where a std tap is 7/16x14 H 3. The last number is the nominal size +/- .0005 so, the -5 means it's .0025 under size.

But, you can clean out the threads with a grade 8 or Allen bolt, with the first threads shaped like pictured.

[frnkeore]

I guess I should add to my above post, that I'm a machinist and the specs I give are from the original Ford drawings.

[Zeke3]

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Originally Posted by frnkeore

But, you can clean out the threads with a grade 8 or Allen bolt, with the first threads shaped like pictured.

Thanks Frankfort for the thread information and tip on making a thread chaser. I always cut slots in a cap screw with a hacksaw or a Dremel to make thread chasers in the past.

[busmania]

Can anyone tell me what the thread size/pitch is of the female rubber brake hose by the middle crossmember? Thank you.

[Mart]

7/16 24 same as the female ends in the front hoses. Standard thread for a 1/4" tube fitting. Used with double flares.

[Ziggster]

Originally Posted by busmania

Got my first answer

Rear axle nut - 5/8 x 18

That is also the same size for the generator pulley on my C59A. Ordered a tap/die set for this specific size off of Amazon, because the threads on my orig Ford replacement pulley were not made deep enough to fit on the armature shaft.

[busmania]

Thank you! 7/16-24 is what I thought but wanted to be sure.


Updates

-Rear axle nut - 5/8 x 18
-Steering column nut - 5/8-18. Standard 5/8 UNF thread.
-Female rubber brake lines - 7/16-24

Thanks to frnkeore above for this helpful info in head studs.
Regarding the stud holes for the head, they are tapped to .0025 under the nominal pitch diameter and the drilled hole is to be between .349 and .353.

The proper tap will be 7/16x14 H-5, where a std tap is 7/16x14 H 3. The last number is the nominal size +/- .0005 so, the -5 means it's .0025 under size.

But, you can clean out the threads with a grade 8 or Allen bolt, with the first threads shaped like pictured.

[coolcoupe]

Looking for the threads per inch for the master cylinder cap. Anyone ?

[coolcoupe]

Looking for the threads per inch for the master cylinder cap. Anyone ? 1947 car