[Farmall] Tap / Die Set

[Karl Olmstead]

Tony, I've found the cheap tap and die sets to be very unreliable.  The taps 
were inaccurate, so they loused up the threads instead of cleaning them up. 
One way to save some money is to buy a set that contains only SAE threads. 
Most sets have metric as well as U.S. threads, and unless you're doing a lot 
of work on relatively new vehicles, you won't use metrics much.

There are many different types of taps offered.  Some work best for cutting 
new threads, some work only in through holes, and some (called bottoming 
taps) work best for rethreading holes that don't go all the way through a 
casting.  Bottoming taps are the most useful for old tractor restoration, 
but they are almost useless for cutting new threads.

If I were buying a set of taps and dies today, I'd look for an SAE set, both 
coarse and fine thread (NC and NF), ranging from 1/4-20 up to about 9/16 
inch.  That'll cover 90% of what you'll encounter on a Farmall.  Next 
priority would be smaller taps, down to 10-32.  About the smallest thing 
used on a Farmall is 8-32; a few of the magneto screws.

Instead of chasing rusty bolts with the die set, I use a wire wheel on the 
threads first, then finish up by running the bolt through a die.  Running 
all that rust and dirt through a die will dull its cutting edges very 
rapidly.

Don't twist a tap too hard when you're using it (and DON'T bend it!!).  If 
you break it off in the threaded hole, it'll be a 'beach' to get out. 
They're almost glass hard.  You can usually shatter them with a punch if you 
do have to remove a broken one.

Some sources:

www.use-enco.com
www.rutlandtool.com
www.mscdirect.com


-Karl
-------------------

> Hello,
>
>  I am nearing a phase where I may start to put my F-20 together.  Before I 
> do, I think I should be chasing the threads and the like.  I have never 
> used or owned a tap & die set.  How large a set do I need and what should 
> I be looking for?
>
>  Thanks,
>
>  Tony