Record 74 auto vice. Bolts for jaws

[JokerZero]

Hi,
I have given up on getting a new set of jaws for my record 74 auto vice as the 4 inch sets sold on amazon and ebay are not even close to fitting.

However I still need 4 bolts to put the cleaned up originals back on.

These measure on my calipers as 0.3 of an inch which is about 5/16 or 7.7 mm in new money.

Now I have tried a few 5/16 threads but nothing seems to work, there are quite a few imperial threads and trawing the forums record don't seem to have consistently used any one thread.

Thread pitch on the remains of these measures at 0.404 for 10 threads so 0.0404 inches per thread or 1.027 mm.

Any idea as what thread type these are?

Thanks in advance
Trev

 

[Trevanion]

5/16" UNF?

 

[topchippytom]

Anything on the bay that will match them.

 

[Eric The Viking]

My Record is probably 1970s. I was surprised to find the threads for the jaws are metric, M6, IIRC.

So it rather depends on when it was made I guess.

 

[Nigel Burden]

IIRC my Record 83 has 5/16 Whitworth screws.

Nigel.

 

[Trevanion]

Well, my answer came from judging from the pitch given it would be a 24TPI thread, 5/16" UNF is 24TPI whilst 5/16" BSF is 22TPI.

 

[JokerZero]

Hi, thanks for the replies.

The script "Auto vice" on the side tells me is pre 1950, so I think metric was still a way off for Record.

and the measured dia of 7.7mm also suggests not a metric.

I will try a 5/16 UNF - I know that whitworth does not fit.

Thanks

Trev

 

[nabs]

I bought a set of Irwin 4'' jaws to replace mine too - I can see they are not as deep but assumed the holes would line up. Do they not fit at all?

As it happens I could not remove the old screws in order to check. Even hefty whacks with an impact driver would not budge them. How did you remove yours?

 

[JokerZero]

Hey Nabs
I drilled mine out - eventually established that the thread is a 5/16 25 tpi thanks to the posters on this forum (thanks!) and the vice is up and running.

So I bought some 5/16 countersunk 1 inch screws and discovered there was no way these were going in the jaws which looked more like they were drilled for a shallow pan head.

No such screw on the internet so, I buy a large hss countersink bit and take on the jaws.

Only to discover the old screws were so welded in that whats I was trying to countersink out was still the remains of the old screws.

Once that battle was over, I took a 5/16 24 tpi tap to the holes that were pretty rusty.

Cleaned up the old jaws on a wire wheel and put the thing back together.

Even then the holes did not align well and more whittling of metal was required before everything would seat nicely.

If I had to do this again Id be very tempted to leave the jaws in place and mask them for painting.

 

[JokerZero]

https://photos.app.goo.gl/oBznHsU8FkK3oCQt8

Thanks again Trevanion for identifying the thread !

 

[porker]

I bought a bag of screws that I used to hold the jaws on my old record. Do these look about right? Difficult I know as there is nothing for scale but i remember they were some special imperial thread.

Just measured them. Across the threads they are 0.308". They are 1.733" long. I seem to recall they were a bit long and I cut them down a bit. Measured the thread pitch but I think it is wrong. 10 threads measures around 0.533" over 10 threads.

 

[JokerZero]

Yeh they would need cutting down - an inch long is plenty.

Gauge sounds right at 5/126 but that thread pitch your quoting is more like 19tpi. the ones I have in there are fine - if not quite genuine as I have put in hex socket heads instead of slotted, but not too worried about that detail and options for that size in the UK are limited.