Tap size for tie rod

[Bob from Northport]

Can anyone advise the correct tap size for the tie rod and drag link whrre the plugs thread into the ends. i.e. the thread size of the plugs.

Thanks!!

Bob

Merry Christmas to all the Model A guys!!!!!!!

 

[Kevin in NJ]

When dealing with the Ford threads you need to ask one more question.

Which standard thread was used?

Ford tended to use higher tolerance threads. I have learned it is a big mistake to use standard tap and dies on even the common parts. The threads get real loose real quick.

From the wiki on threads:

Classes 1A, 2A, 3A apply to external threads; Classes 1B, 2B, 3B apply to internal threads.
Class 1 threads are loosely fitting threads intended for ease of assembly or use in a dirty environment.
Class 2 threads are the most common. They are designed to maximize strength considering typical machine shop capability and machine practice.
Class 3 threads are used for closer tolerances.


I believe tap and die sets are class 1 and Ford used the next 2 levels.


I use a wire wheel and thread file to clean up external threads and a 90* pick to clean the internal threads any more.

Just the other day I was looking at the rad rods. I had cleaned up a pair with a tap a few years ago and noticed the nuts had way more play on them then the untouched clean originals.

 

[PeteVS]

I'm working on a couple of modified cars using later ('48 and earlier) suspensions and I picked up a pair of 11/16-18? taps from Speedwaymotors.com, both left and right hand. I'm using steel tubing 7/8 OD x .120 wall for the drag link and tie rods. This combination accepts the '48 Ford tie rod ends.

SORRY- I MISREAD THE QUESTION!

 

[Glenn C.]

If you have a used plug laying around with decent threads, you can use your die-grinder or even a hack a fine blade hack saw to cut three grooves across the threads to form your own thread chaser. works for me.

 

[Ron in Quincy]

Bob,

As Glenn said, use and old plug with good threads; I just cut 3 grooves using my grinder stone edge; welded it to a 1/2" socket. Works great and I have a permnate tool for future use.

Ron

 

[Mike V. Florida]

When dealing with the Ford threads you need to ask one more question.

Which standard thread was used?

Ford tended to use higher tolerance threads. I have learned it is a big mistake to use standard tap and dies on even the common parts. The threads get real loose real quick.

From the wiki on threads:

Classes 1A, 2A, 3A apply to external threads; Classes 1B, 2B, 3B apply to internal threads.
Class 1 threads are loosely fitting threads intended for ease of assembly or use in a dirty environment.
Class 2 threads are the most common. They are designed to maximize strength considering typical machine shop capability and machine practice.
Class 3 threads are used for closer tolerances.


I believe tap and die sets are class 1 and Ford used the next 2 levels.


I use a wire wheel and thread file to clean up external threads and a 90* pick to clean the internal threads any more.

Just the other day I was looking at the rad rods. I had cleaned up a pair with a tap a few years ago and noticed the nuts had way more play on them then the untouched clean originals.

Very true be careful in what you choose.

 

[bobscogin]

There's a handy tap drill size calculator here: http://www.newmantools.com/tapdrill.htm
Enter diameter, pitch, and percent of thread and there ya' go.

Bob

 

[Bob from Northport]

Thank you, Don. Merry Christmas to you as well!!

 

[Terry NJ]

Commendable! You noticed! However, if you use the spilt or adjustable dies, you can cut a thread that's tighter than a clam's..., and that's water tight! It all depends on how far into split of the die you turn the pointed screw of the diestock. That's assuming you have a diestock with three set screws in it. It'll be the second screw. If you have an old one with only one locking set screw and a solid die, you're out of luck.
Terry

When dealing with the Ford threads you need to ask one more question.

Which standard thread was used?

Ford tended to use higher tolerance threads. I have learned it is a big mistake to use standard tap and dies on even the common parts. The threads get real loose real quick.

From the wiki on threads:

Classes 1A, 2A, 3A apply to external threads; Classes 1B, 2B, 3B apply to internal threads.
Class 1 threads are loosely fitting threads intended for ease of assembly or use in a dirty environment.
Class 2 threads are the most common. They are designed to maximize strength considering typical machine shop capability and machine practice.
Class 3 threads are used for closer tolerances.


I believe tap and die sets are class 1 and Ford used the next 2 levels.


I use a wire wheel and thread file to clean up external threads and a 90* pick to clean the internal threads any more.

Just the other day I was looking at the rad rods. I had cleaned up a pair with a tap a few years ago and noticed the nuts had way more play on them then the untouched clean originals.