Record No 3 vise question

[gf0012-aust]

I’m currently restoring a Record No 3 vise which has a main screw which has been compromised and needs rethreading or chasing. Ive got a couple of these, so would rather buy a tap and die set to keep for ongoing use rather than just buy new spares which may not be as good in quality anyway.

i am wondering if anyone knows what size and type thread is used. The old english records and new irwins use the same main screw and nut (TC3)

unfort can’t get any assistance from Irwin. Have tried the local fastener shop but they only have UNC UNF metric, no acme threads. Its around 16mm / 5/8th and 12TPI

 

[PierceA]

Post a good photo of the screw along side a measuring tape or ruler. The profile of the thread should be apparent as well as being able to count threads compared to the ruler. Use an inches scale, since most likely they are an Acme thread which are sized by x-threads per inch.

PierceA

 

[gf0012-aust]

Thread dia shown in metric and imp, tpi in imp

 

[plewlandsbob]

Have a look one here. This is thread on a British forum , about bench vises. It even has a few Kiwi members

Show us your bench vice(s)

What can I say. I finally succumbed to temptation and started a thread to compliment the benches and lathes threads, (both linked to below). :D http://www.mig-welding.co.uk/forum/threads/show-us-your-lathe.32978/ http://www.mig-welding.co.uk/forum/threads/our-work-benches.48442/ My current...

www.mig-welding.co.uk

 

[gf0012-aust]

Thanks

 

[gf0012-aust]

According to irwin response, its

The diameter of thread is 0.61", the pitch is 0.08", the lead is 0.17"

not exactly narrowing it down as none of the thread guides refer to “lead”

 

[timgunn1962]

With both pitch and lead given, it would suggest a multi-start thread and I would sort-of assume it's a 2-start thread? Pitch of .08" will be between adjacent threads, but when you turn the screw, it's only running on one of the 2 threads and moves by twice the pitch?

Of course the numbers don't add up accurately and I'm just some random guy on the internet who's only really guessing. It should be easy enough to check on whatever you have there.

 

[gf0012-aust]

All started because i wanted to buy a die to chase the thread. I wanted to buy an off the shelf tap and die. I guess i will just have to see whether i can run a vanilla OTC thread chaser over it