been trying all over the world (well ebay at least) to get some 3/32" whitworth screws for a pair of synchro receivers. Lots of suppliers say there's no such thing and the rest don't have anything. Could anyone help please? I do know that the size exists because you can buy a tap and die in 3/32" BSW. And I have some already in the synchro connections UNC is close but won't go in, can't tap the connectors as the e got fine brushes attached. They're 2.4mm outside dia 48 TPI about 12mm long pan heads

 

Perhaps here: http://www.namrick.co.uk/acatalog/Home_B_S_W__HT_Set_Screws_23.html

 

Perhaps here: http://www.namrick.co.uk/acatalog/Home_B_S_W__HT_Set_Screws_23.html

Thank you very much for this information- I'll give them a try first thing in the morning.
Kind regards
Keith

 

If that fails, what size and pitch do you need? I have a very nice Smart and Brown lathe from 1965-1966 that is all Whitworth. I bought a bunch of spares awhile back (1980's) and will try to locate the source if that other lead fails. Outside diameter and pitch will be sufficient. Do they have hex heads or slotted cheese heads like in your gyro?

John

Oops. Just read your post #1. I will look into it further. John

Edit#2: Some microscope threads are still Whitworth, because of the greater grip of 55° vs. 60° with fine pitches. You might consider contacting a microscope dealer.

 

Diameter
inches
3⁄32


Threads
per inch Tap
drill
48 50

http://www.sizes.com/tools/thread_whitworth.htm

 

I tried Namrick and they dont have any and cant source them anymore. at least it confims that it is a valid size. Microscope dealer is good info. Ill give it a try. the screws are for a Synchro Reciever for the electical connections. THe ones in the gyro are all BA. thanks again for your help. regards Keith

 

BTW, the screw heads you show are probably called cheese head.


Pan head is flatter and more rounded. Fillister is very similar, but often is more rounded (http://www.mcmaster.com/#machine-screws/=uulbm2 ).

That distinction isn't going to help you find an exact replacement. The question is whether you want an exact replacement for a true restoration or something that looks about right but is not really a Whitworth?

For the former, you will probably end up making it. If you can get a 3-48 NC cheese head screw, you might be able to chase it with the Whitworth die to get a fit. However, there will be several threads near the head that the die won't fully reach. You could fix those or do the whole treading with a small lathe.

If your choice is the latter, an alternative would be to drill the hole to the minor diameter of a 3-48 NC, then run a tap down it and use a 3-48 NC screw.

I could not find the source of the Whitworth screws I got for my lathe. It likely it was a British car parts dealer. Sorry, I can't be much help.

John

 

Ask Tracy for help

http://www.tracytools.com/other-products

 

Thanks for this info, John. the heads are not that important its only to get it wired up, not for restoration. unfortunatley I cant drill out the holes as the connectors are also super fine brushes that go down into the motor windings.
so im only left with the screw option. I will probably try to make some by tapping some slightly larger ones down. I have literally tens of thousands of screws gathered over umpteen years, and not one will fit these! could you credit it?
youve been a great help - thanks. Keith

 

Ask Tracy for help

http://www.tracytools.com/other-products

thanks for the link, Ive just ordered a Die, so I'll be able to make some screws. cheers Keith

 

By the way are you sure you don't mean a BSF screw (more usual in that size)

http://en.wikipedia.org/wiki/British_Standard_Fine

What length and material do you need?

And is that Cottingham, Yorks or Cottingham, Northants?

 

By the way are you sure you don't mean a BSF screw (more usual in that size)

http://en.wikipedia.org/wiki/British_Standard_Fine

What length and material do you need?

No I have some BSF and they are finer threads and slightly larger. any material would do (metal!) even unobtainium as long as its not too expensive length is about 12mm, although obviously I could nib some off longer ones

 

Here a good list of suppliers

http://www.meridienneexhibitions.co.uk/exhibitors.php?type=trade&id=0000000007

 

By the way are you sure you don't mean a BSF screw (more usual in that size)

http://en.wikipedia.org/wiki/British_Standard_Fine

What length and material do you need?

And is that Cottingham, Yorks or Cottingham, Northants?

Cottingham East Yorkshire

 

Here a good list of suppliers

http://www.meridienneexhibitions.co.uk/exhibitors.php?type=trade&id=0000000007

Hello again, I didnt manage to get any screws from any of those suppliers but I got my die from Tracy Tools and made the first screw from brass, - only nine more to go! thanks again Keith

 

You'll be an expert by number 10 then.

-

 

You'll be an expert by number 10 then.

-

probably just have sore fingers!

 

probably just have sore fingers!

Sore fingers is one reason why God created vises and tapping wrenches and ...

 

I thought apprentices was the reason why God created vises and tapping wrenches.

-

 

Used fingers on first one because I was in the warmth of my mancave in the sky. Will now venture outside to icy workshop to retrieve mechanical assistance aka die stock vice,oil etc. (well, after breakfast maybe!)