British Taps & Dies for a Yank!

[fltenwheeler]

Hi All

I am going though some boxes of British taps and dies that were giving to me. Most are in box sets, but I have a lot of them that are loose.

I found some marked 5/16x40WF, 1/4x32WF, 3/8x40WF. Are these the same as ME?

Thanks

Tim

 

[doubletop]

Tim

It sounds like it, its the right pitch (32 and 40 TPI). I'm not sure what the WF refers to though. Give it another 4 hours or so and you'll get lots of answers

Pete

 

[Swifty]

To my understanding it means Whitworth form or Whitworth fine, one or the other.

Paul.

 

[Holt]

It's Whitworth form, which means that it's 55 deg.
Here you have a link to a discussion on the same subject, but i have to warn you it's 11 pages long, but if you have the time, it's quite amusing.
http://www.theminiforum.co.uk/forums/index.php?showtopic=120177&hl=Whitworth

 

[fltenwheeler]

OK; I am going to go with WF to mean Whitworth Form not Whitworth Fine.

How on to the next one. Taps and Dies marked 5/32 ME and 3/16 ME should mean 5/32 40TPI ME and 3/16 40TPI ME?

Tim

 

[rkepler]

How on to the next one. Taps and Dies marked 5/32 ME and 3/16 ME should mean 5/32 40TPI ME and 3/16 40TPI ME?

Model Engineer - there are specifications for 32 and 40 tpi threads in Whitworth form used mostly for pipes in models.

 

[SteveO]

I would go with Whitworth Form, but if there is an arrow on any of them it could be "war finish" from WWII. Used to see this in the UK on a lot of tools and machine tools 50 years ago.

SteveO

 

[fltenwheeler]

I would go with Whitworth Form, but if there is an arrow on any of them it could be "war finish" from WWII. Used to see this in the UK on a lot of tools and machine tools 50 years ago.

SteveO

I will look for an arrow. Some of the tools have receipt's from the 50s and 60s.

Tim

 

[GWRdriver]

on to the next one. Taps and Dies marked 5/32 ME and 3/16 ME should mean 5/32 40TPI ME and 3/16 40TPI ME?

Hi Tim,
There's no pitch indication on those because 5/32 and 3/16 are only scheduled in 40tpi.

In looking at my thread information to see if I could contribute anything further to the thread (I can't) I discovered something about the ME threads I had never noticed before and is unlike any other thread I've seen. Within each ME thread pitch (26, 32, & 40tpi), the depth of thread always remains constant. In other words the depth of thread for 40tpi in all diameters is .016". In most threads the depth varies continuously and proportionately with the diameter.

 

[Blogwitch]

Actually Harry, you can get the smaller ME sizes in 32 tpi as well. I have full sets of both 32 & 40 tpi, from 5/32" to 1/2", with the 40tpi set starting off at 1/8"

http://rdgtools.co.uk/acatalog/32TPI_TAPS_AND_DIES.html

http://rdgtools.co.uk/acatalog/40TPI_TAPS_AND_DIES.html

You can also get tapered pipe threads in ME as well, but their pitches are a little haphazard.

ME Tapered Pipe MTP - 1/8x56, 5/32x48, 3/16x40, 1/4x40, 5/16x27, 5/16x40, 3/8x40 (for gas-pipe tapered fittings)


John

 

[rkepler]

In looking at my thread information to see if I could contribute anything further to the thread (I can't) I discovered something about the ME threads I had never noticed before and is unlike any other thread I've seen. Within each ME thread pitch (26, 32, & 40tpi), the depth of thread always remains constant. In other words the depth of thread for 40tpi in all diameters is .016". In most threads the depth varies continuously and proportionately with the diameter.

Perhaps I'm not understanding you but depth of thread is a constant for any thread regardless of the diameter it's cut on, diameter changes the major, minor and pitch diameter (obviously) and the thread helix angle.

 

[fltenwheeler]

Hi All

Ok here is another one.

Is a 1/8" BSW the same as a 1/8" ME?

Is a 3/16" BSF the same as a 3/16"x32 ME?

Tim

 

[rkepler]

Is a 1/8" BSW the same as a 1/8" ME?

Same major, minor and pitch diameter and thread form. I'd say they're the same in every aspect other than the names.

Is a 3/16" BSF the same as a 3/16"x32 ME?

3/16 BSF is 32tpi, 3/16 ME is ordinarily 40tpi but if a 3/16 ME were supplied in the right form and 32tpi it would be the same as 3/16 BSF.

 

[Blogwitch]

Tim,

You are quite correct in your assumption.

Rk,

If you had read my last post, it states that all standard sizes, except the 1/8", can come in either 32 or 40 tpi


John

 

[Jasonb]

John, if you take a look at Tracy Tools you will see they list 1/8x32 and 1/8x26 under specials but they are in effect ME equivalents.

Though I don't think there would be much of a core dia left after threading 1/8x26

J

 

[Blogwitch]

You're quite right Jason. I don't think I would ever use those specials, but at least I now know they are available.

The 40tpi ones are perfect for doing imperial tooling as it is the same pitch thread as used in imp micrometers, and it gives a nice round 0.025" feed per revolution.

The only problem is that I have found, all the Tracy Tools ME thread carbon taps that I possessed actually cut oversize, and the dies undersized. I tried opening out my die holder to make the thread larger, to compensate for the larger tapped holes, and the dies actually split before I ever reached a good larger fitting size. I have now got rid of my sets that I bought from there, as they made all my fittings too loose.
My T&D ones are perfect in every way for what I want to do.


John

 

[GWRdriver]

Harry, you can get the smaller ME sizes in 32 tpi as well.

John,
I'm not surprised. For purposes of this thread (no pun intended) I consulted this handy little booklet produced by AJReeves some 20 years go. No doubt suppliers can produce additional sizes faster than the publication could be updated.

 

[fltenwheeler]

Hi All

Every manufacture has their own preferred sizes.

Stuart lists:
1/8", 5/32", 3/16", 7/32", 1/4" in 40 TPI ME.
1/4" in 32 TPI ME.
1/4", 5/16", 3/8", 7/16", 1/2", 5/8" in 26 TPI Brass.
Along with:
2,4,5,6,7,8 & 10 BA

Tim

 

[Blogwitch]

You're quite right Harry, in fact, some retailers are now up to 5/8" in the ME sizes, or maybe even more.

But they really are a beautiful and easy size set to use, I just love the fine 40TPI threads on largish items, it sort of gives them a nice precision feel. Perfect threads for filler caps etc.

Tim,
I think you might find that Stuart are quoting only those sizes because maybe they are the only sizes they use in building their models, but don't quote me on it.


John

 

[smfr]

John

Darned if I didn't just order some BSB taps and dies from Tracy Tools, after balking at the £75 shipping charge to the US from T&D. I'll have to see if they cut under/oversize like the ME ones you describe.

Simon