Wassup?

[Yens PhillipsParticipant @yensphillips42530]

Hellooooo Wembley!..or Hi everyone…should I be more normal as a newcomer?

Glad to be a member of what looks like a great forum, with great folks whom have a wealth of knowledge. I'll even try to contribute some myself. Still an apprentice, hopefully have that finished soon and will be staying on with my firm.

Got a question for you all. How easily can i get hold of small BSW screws? I recently picked up a Parkinson No.8 Quick Release Vice. It needs a lot of work (rust).

There is an attachment with a missing screw…the thread diameter is 4.36mm/0.17188".

According to this site: (See page 7, Chart No.10, Left hand column, 11/64&quot
This screw was a "Small Whitworth Form Thread".
http://www.gerardsgarage.com/supportfiles/Threading_Tables.pdf

I can't find this anywhere online. Only larger BSW bolts.

Can anyone help out?

Really Appreciate any help,

Best to you all,

Yeti!

[Yens PhillipsParticipant @yensphillips42530]

Here’s Johnny!

[Anonymous]

I can't imagine you're going to find 11/64" BSW off the shelf. It lists as 32tpi so it should be straightforward to screwcut what type of screw is needed.

Andrew

[David George 1Participant @davidgeorge1]

Hi Yeti What sort of length and form are we talking about. Slotted head screw, Hex head bolt or cap screw. I would have a look at 5mm thread type as the pitch but not diameter is nearly identical and either turn down and re cut thread on a screw 5mm diameter or tap out to suit new 5mm bolt. The pitch of 0.031inch is equal to 0.810 mm and 5mm thread pitch is 0.8mm so near it wouldn't mater.

David

[Yens PhillipsParticipant @yensphillips42530]

Thanks Andrew,

Countersunk head, 1/2" long. Preferably slotted for flat head screwdrivers. But Cap, or Phillips are fine either way.

I've had a quote for one to be made, and its coming out at £21.50. But as a bespoke job for a machine shop, thats understandable.

Cheers,

Yens

[Yens PhillipsParticipant @yensphillips42530]

David,

That sounds like a good solution. I'd consider drilling and tapping as a final solution, because I'd like to be as original as possible…am I nostalgic? Unfortunately I've got no lathe access.

Edited By Yens Phillips on 07/11/2017 16:31:17

[Mike PooleParticipant @mikepoole82104]

How convinced are you that it is Whitworth? Many companies used BA sizes below 1/4".

Mike

[Yens PhillipsParticipant @yensphillips42530]

Hi Mike
​…Now you've said that I'm not sure…I'll have a look. I assumed it would all be BSW.

[Tony Pratt 1Participant @tonypratt1]

What's the TPI,. could be 10-24 or 10-32 possibly? Diameter is small but could be.

Tony

[BazyleParticipant @bazyle]

Mike has it. 2BA. common as nuts. No way is someone going to make a product with a weird Whit thread. Many of these sizes may exist in tables for completeness but were never produced or used unless someone was needing to make it so that spares were single sourced. Not going to happen on a bog standard vice.

[Howard LewisParticipant @howardlewis46836]

Mixing metric hardware, or even Unified, on an heritage Imperial standard item would be anathema to me.

But IF the thread form IS Whitworth, it can't be 2 BA, (Different thread forms, Whitworth 55 degrees vs 47.5 for BA)

2BA is 4.7mm (0.185"  dia,

We are missing a vital clue. Can you measure it's twin, to find how many tpi? (If you've already had a quote, you ought to know this.)

British Standard Brass threads are Whit form, 26 tpi. Don't confuse with British Standard Cycle, which are 26 tpi but 60 degree form.

At 0.1711 dia it looks too undersized to be 3/16, BSW , BSF, or Model Engineer, (either 40 or 32 tpi) and is WAY too small for 1/8 BSP.

At 0.1711 dia it is too large to be 8-36 UNF or 8-32 UNC (0.164"  and too small to be 10-32 UNF or 10-24 UNC (0.190" .

So it may be a "special" of some sort. (Edited to get rid of emoticons instead of closing brackets. GREMLINS!)

Howard  OR SO I THOUGHT!

Edited By Howard Lewis on 08/11/2017 20:43:47

Edited By Howard Lewis on 08/11/2017 20:44:29

Edited By Howard Lewis on 08/11/2017 20:45:08

[Anonymous]

Less than a thou different from 11/64.

Andrew

[Yens PhillipsParticipant @yensphillips42530]

Gah! So much to consider! I'm glad I live in a world where we have metric standards. I'm learning so much here.

The hole measures in at 4.2mm. Unfortunately, the screw was lost (not by me!). So I've no real way of telling what the TPI really is.

I've just ordered a few 2BA and 3BA screws quite cheaply. Should be here tomorrow. I'll let you all know how I get on and hopefully add some photos of the work thats gone into it all . Thanks for your advice all!

Yens

[Danny M2ZParticipant @dannym2z]

Posted by Yens Phillips on 07/11/2017 14:21:34:. Still an apprentice, hopefully have that finished soon and will be staying on with my firm.

Welcome to the forum Yens and well done to pick a trade that requires manual skills to fit the parts.

Not many apprenticeships around nowadays – you picked wisely.

As I tell my friend's children "Don't worry about robots – learn how to design and repair them!"

* Danny M *

[Author]

Posts