66 starter relay bolts

darth_linux

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I know this is a reach, but does anyone know the size and thread COUNT for the two starter relay bolts on a 66 Chrysler? Trying to replace a missing bolt at the same time that I buy a new starter relay, and do it in one trip instead of two trips. Thanks in advance if you know.
 
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For the record, thread count is not the same as thread pitch.
Now pitch needs to be defined. LOL.

Thread pitch is the amount of distance from one spot on a thread to the same spot on the adjacent thread. Or in other words, how much that screw will move in one turn.

Geez... I'm getting flashbacks of dropping thread wires......


screw_thread.png
 
What the heck..,
What is thread count? Thread count refers to the number of threads or strands per square inch of fabric, counting horizontal and vertical threads. It indicates how tightly woven the fabric is. This number is an approximate indicator of fabric softness, but does not always translate to higher quality.
 
Thread edited for clarity.
Actually, if you really want to be clear.... It "threads per inch" or TPI for SAE threads. Example: 5/16-18 where 5/16 is the diameter and 18 is the TPI. Want to know the pitch? Divide 1 by the TPI.

With metric threads.... Example: M10 x .75.... M10 is the diameter and .75 is the pitch.

Now my head is starting to ache thinking about things like triple start Acme threads and British straight pipe threads that I used to have to play with. Shudder...
 
H
Actually, if you really want to be clear.... It "threads per inch" or TPI for SAE threads. Example: 5/16-18 where 5/16 is the diameter and 18 is the TPI. Want to know the pitch? Divide 1 by the TPI.

With metric threads.... Example: M10 x .75.... M10 is the diameter and .75 is the pitch.

Now my head is starting to ache thinking about things like triple start Acme threads and British straight pipe threads that I used to have to play with. Shudder...
One word: Whitworth.
 
H

One word: Whitworth.
Yes... British pipe threads are 55 degrees like Whitworth.

We had a customer (I was a partner in an A2LA accredited gauge calibration lab) that had all these very bizarre British thread gauges. Some were old and the rest of the world hadn't used them in years. We got their work because we were one of the few places that could figure out the math needed to check them. The secret was that a couple of us did some Excel sheets where you just had to plug the raw measurement numbers in. Once we did that, any of our guys could check them and give the customer all the data. It was some homework though... and we had large binders full of thread measurement criteria and tolerances.

Geez... It's been 7 1/2 years since I had to think about that stuff.... I might have to lay down now.
 
My favorite is the Germans. They use"PG" which loosely translates to Panzer Grade! A different thread configuration for the tanks!
 
British threads
As a youngster working on bicycles, I had to learn about Cycle Institute bolts. These were commonly found on English bikes. Even the bike shops of forty years ago did not stock these fasteners.
 
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