Various thread pitch’s needed

busmania

busmania

Well-known member
Various thread pitch’s needed

I have several different threads through the car that need to be chased. Yes my kit has the measurement tool but the last one I tried it on I screwed up so until I am more familiar with that I would like to double check my work with you all. I will keep this thread running as I go to hopefully help others in the future. Can anyone help me with the following? Also, if you know random thread pitches of other hardware, feel free to post it, and I will list it all together so it is aggregated. As always, thank you!

First, I need the rear axle threads where the outside axle nut holding the drum on f goes. Anyone know it? It looks like mine are pretty buggered up.
 
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Re: Various thread pitch’s needed

On a '48 Ford rear I've got in the garage the treads are 5/8 national fine.
 
Re: Various thread pitch’s needed

Heck of it is... on rear axles, and on steering columns, if the threads are REALLY messed up from hammering, then it's my opinion that a thread chaser does a little more damage, than good. So, what I've done for these situations, is to take a fresh, new nut that fits the thread, saw it open, clamp it around the axle or steering column, squeeze it back together as much as possible, and weld the saw cuts closed. Then, heat the damaged threads cherry red, and work the nut, backing it off a little at a time. The point, or goal, of this, is to try and re-form the old threads. After completing this, then use the thread chaser, as shown in Sheldon's post, above. Obviously, opinion and my experience. I have only done this three times, twice on steering columns, once on an axle.
 
Re: Various thread pitch’s needed

Zeke3 said:
There was a recent discussion that includes some suggestions to correct damaged threads. Also, the thread size and pitch for the axle may be included in this discussion.
https://www.fordbarn.com/forum/showthread.php?t=325196
Click to expand...

Yep, that’s what got me thinking and I didn’t want to hijack someone else’s thread.

bobH said:
Heck of it is... on rear axles, and on steering columns, if the threads are REALLY messed up from hammering, then it's my opinion that a thread chaser does a little more damage, than good. So, what I've done for these situations, is to take a fresh, new nut that fits the thread, saw it open, clamp it around the axle or steering column, squeeze it back together as much as possible, and weld the saw cuts closed. Then, heat the damaged threads cherry red, and work the nut, backing it off a little at a time. The point, or goal, of this, is to try and re-form the old threads. After completing this, then use the thread chaser, as shown in Sheldon's post, above. Obviously, opinion and my experience. I have only done this three times, twice on steering columns, once on an axle.
Click to expand...

Good info. The thread link above gave me that idea too but I have not yet read about heating at Cherry red. Makes sense. I will give it a go. One IGood info. The thread link above gave me that idea to but I have not yet read about heating at Cherry red. Makes sense. I will give it a go. One side is pretty jacked up.
 
Re: Various thread pitch’s needed

Frankly, and in my opinion, buggard up threads from years of hammering and farmer fixing are beyond restoring. The metal is most likely work hardened, brittle, and cracked.
Reforming compromised metal such as this is not a good idea particularly with critical items such as steering shafts and axles. A better approach would be machine off the old threads, tig weld and build up the diameter to allow turning and re-threading. This is not a complicated procedure and I don't believe the tapered ends of axles or steering shafts were heat treated originally so this should not be an issue. This is what i have done, again , my opinion.
 
Re: Various thread pitch’s needed

There are a few threads on the car I do not want to chase. The axle thread is one. If it is absolutely necessary I would use the old split thread cleaning tool that hinges open and has a thumb screw to hold it closed. A hand die will remove metal from the threads which is not what you want to do to these thread that get tightened to about 200"/#
A pitch gauge will be helpful to select the proper tap or die for thread chasing.
 
Re: Various thread pitch’s needed

This is the set I bought to have and use for this purpose AND instead of my general "Tap & Die" set. Great for chasing threads in block after they have been cleaned as well!!!
 

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Re: Various thread pitch’s needed

It's been a couple of years so forgive me if I have something wrong here.

The 7/16 threads on brake fittings all appear to be NF (fine thread) BUT the "nuts" on FLARED fittings are not. The thread where the rubber hose screws into the front wheel cylinder IS 7/16 fine but not for the where the flared tubing screws into a rear wheel cylinder. Drove me crazy for a while.

By the way, is that hinged tool for axle threads available anywhere?
 
Re: Various thread pitch’s needed

Look at post #9.I posted one that's on EBAY. There are several listed.Here is a pic of it.
s-l400.png
 
Re: Various thread pitch’s needed

The tool that Deuce lover, and Terry K refer to is the right way to fix the problem. I have 2
of these tools, and they have served me well. What is your location ? Perhaps someone in your area has this tool and could help you.
 
Re: Various thread pitch’s needed

I have a very complete tap and die set. My issues are not with using that it’s using the measuring tool that comes with it to measure the thread pitch.

I dont have one of those listed in the last post but want one but can’t find them because I dont know what they are called and I dont think anyone in this thread or the other has called them by their name. What’s the name of that tool? I’ve never been able to come up with an excuse NOT to buy more tools. It’s the wierdest thing.
 
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Re: Various thread pitch’s needed

I use the Craftsman kit I bought when my local Sears was closing paid less then $40 for it. Amazon has one that looks like the Craftsman kit. I use the files as my thread count tool, I lay the file on the bolt or stud and match up the threads.
 

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Re: Various thread pitch’s needed

Fords use SAE threads, UNF or UNC. Most threads in the engine block ate UNC. Same for trans casings.

Rear axles tend to use UNF.

Measure the diameter and the pitch should only be one of two values. One value for UNF (fine) and one for UNC (coarse). Measure the diameter and look up the pitches on the charts. It's actually threads per inch rather than pitch for UNF/UNC. Metric threads are expressed as pitch in mm.

514656


514657
 

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Re: Various thread pitch’s needed

The tool that you need to identify the thread count is a thread pitch gauge. they are readily available, even in the cheapy tap and die sets.
 
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