What size screws for fixing faceplates to Record 52 1/2 vice? - 5/16" BSW don't fit

[scubadoo]

I bought some 5/16" x 1" BSW to fit cheeks to my vice and they don't fit. Callipers show the holes to be about 6.9mm although the rear face holes seem slightly smaller.

Any thoughts?

 

[J-G]

You don't give a great deal of information - such as whether the 6.9mm Ø 'holes' are 'tapped'.

The normal tapping drill for a 5/16 BSW thread would be about 6.8mm so a measured 6.9 would not be unreasonable. Similarly, if the holes are tapped and the thread is BSF rather than BSW then the tapping drill would likely be 7mm - so again, 6.9 seems reasonable.

 

[ChaiLatte]

There is a good write up of the vice here:

https://smallworkshop.co.uk/2018/04/17/record-vice/
It is not clear to me when looking at that page what you want to fit to what.

There are two holes in the front and rear jaws for the wooden jaw pads but they appear to be unthreaded, designed to accept short but fat standard woodscrews.

Can you describe with reference to a photo the hole into which you wish to insert the fastener.

 

[Phil Pascoe]

The holes are threaded, and iirc are indeed 5/16" and imperial, but I'm not certain they're whitworth.

 

[scubadoo]

Thanks. The holes are threaded. Will add a photo with dimensions later.

 

[J-G]

Thanks. The holes are threaded. Will add a photo with dimensions later.

If that is the case then my next test would be to try a 5/16 BSF - which is 22tpi rather than 18 (BSW) - 5/16UNC is also 18tpi so I would expect a BSW bolt to at least go in a little. 5/16 UNF is 24tpi so if you can count the number of thread crests and measure the length of the hole (I assume it is a 'through' hole and not 'blind') you (or someone here) can calculate the tpi.

I suspect that it's very unlikely to be M8 which is 1.25mm pitch (=20.32 tpi) but that is a posibility.

My recollection of fitting Cheeks to this type of vice (many years ago!) is that the holes cast into the diagonal webs were for wood-screws inserted from the 'outside' rather than machine screws, but 6.9mm holes would suggest at least a N° 14 screw.

 

[scubadoo]

It's these holes and the screws will go in a couple of turns then stop. The screws don't seem to go into rear plate though. Seems odd that they would be smaller?
I'll try and get hold of some 5/16 BSF to try.
Thanks all.

 

[porker]

I bought a load of these screws for this very purpose years ago so I know they work on my 52 1/2. Maybe these pictures help (I know they are a bit long) sorry I can’t remember the exact size. I know this has been discussed previously in this forum
Root is about 6.7mm (0.264”) and about 18tpi

 

[J-G]

Those images don't help a great deal. I can count ~8 thread crests but have no way to determine the length of the thread.

I'm now beginging to suspect that the vice has been modified by some previous owner - by drilling out and tapping those two holes - particularly since you say that the holes in the rear jaw are smaller.

Is there any reason that you cannot use woodscrews (fitted from the front) thus ignoring the tapped hole? You are unlikely to find N°14 woodscrews now but you can find short (20 - 30mm) 6mm Ø which would do the job. If the countersink in the front face has been compromised (removed?) by the holes being drilled out you could re-cut them - or even use pan-head woodscrews.

@porker 's post has just come in so I'll see what I can make of that screw.

 

[Phil Pascoe]

Maybe a photo of the vice would help? It would ensure we're comparing like to like - it's conceivable things changed over years.

 

[pe2dave]

Agree with @J-G - I've fitted screws, from 'outside' into wooden cheeks, which makes more
sense than having screw heads facing the work piece?
Crap memory, but I know I used to have 1" #10 screws around, which I may have used. I.e. short and chubbby!

 

[J-G]

@porker 's post has just come in so I'll see what I can make of that screw.

Hmmm... Inconclusive. The two images provide differing results. The one showing 7.800mm - which is marginally undersize for 5/16 but not unreasonable - works out at 18.46 tpi but the other seems to be 20.2 tpi.

Scaling photo's is not an exact science but I would normally expect a better co-relation than that.

20 tpi would be totally non-standard - either in Whit or Unified - so seems unlikely.

It is possible that the thread in the vice itself is damaged of course and running a 5/16 BSW tap through it might just clean it up. One should be cautious with such a plan though and if any real resistance was found - after a couple of turns - then that would indicate an incorrect assumption.

 

[scubadoo]

It's the vice shown in this recent thread.

The reason i wanted to use the threads was that it seems like it would be a pain to have to remove the vice to replace the jaw liners.

 

[pe2dave]

It's the vice shown in this recent thread.

The reason i wanted to use the threads was that it seems like it would be a pain to have to remove the vice to replace the jaw liners.

Only the inner liner? How often do you think you'll wreck the liner? Up to you.
For me, not an issue.

 

[Phil Pascoe]

You bolt through the liners into the steelwork - why would you need to remove the vice?
The vice appears to be the same as mine, or at least the same vintage. This is a poor photo, but the set screws would seem to be 18tpi. The screws in the front and the back are identical.

 

[scubadoo]

You bolt through the liners into the steelwork - why would you need to remove the vice?
The vice appears to be the same as mine, or at least the same vintage. This is a poor photo, but the set screws would seem to be 18tpi. The screws in the front and the back are identical.

I was saying that it would be a pain to remove the vice to change the liners if they were fixed by woodscrews from the back side of the jaws, as the screw head would be hidden. I want to bolt through the liners.

18tpi would be Whitworth? That's what i have and they are not fitting. Did Record use both BSW and BSF on this version of their vice?

 

[Phil Pascoe]

You could fix the rear liner with a wood screw from the outside - just go through the holes in the vice into the wood behind it. I can't honestly remember which threads they are and have no means of finding out.

If you have a spare bolt, put a deep cut up through the threads and relieve the front edge a little (or grind a bit off) making a basic tap -try running that in, it'll pick up any crud in the way. The threads get filled up if the holes aren't used.

 

[scubadoo]

You could fix the rear liner with a wood screw from the outside - just go through the holes in the vice into the wood behind it. I can't honestly remember which they are and have no means of finding out.

If you have a spare bolt, put a deep cut up through the threads and relieve the front edge a little (or grind a bit off) making a basic tap -try running that in, it'll pick up any crud in the way. The threads get filled up if the holes aren't used.

That's a good idea, would never have thought of screwing into the rail of the bench.
And thanks for the advice on trying to clear out the threads.

 

[porker]

18tpi would be Whitworth? That's what i have and they are not fitting. Did Record use both BSW and BSF on this version of their vice?

Just checked and the ones I showed earlier are definitely Whitworth so no use in your case I think

 

[frogesque]

Screw a piece of wooden dowel (roughly trimmed with a knife works perfectly as uneven edges deform more easily) into the bolt hole, when you screw it out again you will see thread marks on the dowel. This will let you count the tpi. From there you should be able to identify the thread.

Our works inspection dept. Used to have a quick setting silicon rubber for taking impressions of internal features such as 'O' seal groves and threads. A bit of chewing gum will also work in an emergency if you let it get reasonably hard, not as good but it does work.

Alternatively, glue wooden face plates to the vice and forget about about them. They should last for years!