Tap for Ryther's chuck on MF No 2 drill

[Robert Hartmann]

Can someone tell me what size tap I need to clean up the threads on a chuck on a MF No 2 hand drill (actually just about any chuck on a MF drill). My eyes are not what they used to be. I counted 22 TPI, but thought I was just off, so I bought a 24 TPI tap and the threads are too fine. Maybe it should be a 20 TPI. I don't see a 22 TPI tap anywhere. Maybe it is special to the hand drills. thanks.

[Jim Koepke]

Howdy Robert,

My time is taken today, so getting into my shop won't be possible until this evening. I will try to remember to see if anyone else has answered and check later if they haven't.

Before acquiring a thread gauge my collection of hardware had a collection of different threaded fasteners for the sole purpose of comparing thread counts. It is much easier than trying to use a ruler to determine pitch.

That may be difficult for many members here when dealing with various international systems of measurement.

jtk

[Cody Cantrell]

Robert,
Are you referring to the spindle threads?

[Robert Hartmann]

Robert,
Are you referring to the spindle threads?

The spindle is fine, its the chuck that needs the threads cleaned up. Someone tried to get the chuck apart (I assume to replace a bad spring) and chewed up the top of the chuck to include the threads. I need a tap not a die.

[Jim Koepke]

Sorry my schedule kept me out of the shop yesterday. Hopefully my time in town today will not keep me out late.

jtk

[Jim Koepke]

Had a bit of time waiting on SWMBO.

The thread is 22 tpi:

343365

Not sure if that is a full 7/16".

http://www.victornet.com/cgi-bin/victor/productlist.html?subdepartments=Special+Thread+Tap s:618,1170,1171

Lists a 13/32-22. They do have a $25 minimum order last time some taps were needed by me. Maybe pick up some other odd sizes like a 12-20 or ???

jtk

[Robert Hartmann]

thanks for the info Jim. I didn't see a 13/32-22. There is a 13/32-20 and -32. If the nut in your picture is 20 tpi, then I should go with the 13/32-20 since that is what I need to clean up. How is it the spindle is 22 and the chuck is 20? Seems odd to me.

[Jim Koepke]

thanks for the info Jim. I didn't see a 13/32-22. There is a 13/32-20 and -32. If the nut in your picture is 20 tpi, then I should go with the 13/32-20 since that is what I need to clean up. How is it the spindle is 22 and the chuck is 20? Seems odd to me.

Robert, my arrow on the the chuck is in reference to the outside threads, ~1-1/8-20, on the chuck where it threads into the shell of the chuck. The inside threads on the chuck are the same 22 tpi as the spindle.

I thought I saw the 13/32-22 there yesterday. They do change often on the site. If something sells out, it is removed and may come back in the future. I have seen that happen with some of the odd sizes purchased in the past.

You might try giving them a call.

Another possibility is a thread chasing tool. It is like part of a tap that fits in buggered threads so they can be forced back to how they should be. To make your own you need a bolt smaller than one to fit. Then one side of it or up to about 2/3 is filed away and what is left is used by hand to reform the threads. In your case finding something with 22 tpi will be the challenge.

Can you take apart the chuck and thread the spindle from the back to see if that might clear the threads?

jtk

[Robert Hartmann]

Jim, thanks for the info and sorry for the delay getting back to you. I started a new job and have "enjoyed" many late nights. Anyway, I took the chuck apart and have run it through in reverse as you suggested which cleared it. I continued from both sides putting some weight on it and it is working pretty good. It would be better with a tap, but it's pretty good. I think I'll call it good.

[Jim Koepke]

Jim, thanks for the info and sorry for the delay getting back to you. I started a new job and have "enjoyed" many late nights. Anyway, I took the chuck apart and have run it through in reverse as you suggested which cleared it. I continued from both sides putting some weight on it and it is working pretty good. It would be better with a tap, but it's pretty good. I think I'll call it good.

Glad it worked out for you Robert.

Some times when it is good enough the best advise is to leave it as is.

jtk