Antique acme threaded vise screw

[Project 2501]

Found this in my grandfather's garage. I know it's the drive screw for a woodworking vise but I can't figure out if it's a shoulder vise or tail vise. Can anyone shed some light please

 

[RTM]

I don't think shoulder. They usually push AWAY vs pull. The way the two fittings are set up in that, I see it pulling.

 

[Project 2501]

I don't think shoulder. They usually push AWAY vs pull. The way the two fittings are set up in that, I see it pulling.

This is definitely designed to squeeze together

 

[Roberts210]

It is a wood working vise for the end of a work bench.

 

[PBCampbell]

Difficult to tell for sure from those photos, but those look like square threads, not acme.

 

[Farmer J.]

I think it is set up to push, look at the direction of the countersinks in the screw holes in the nut flanges.
I agree with Roberts210
Looks like one of these to me:

Tail-Vise Screw - Lee Valley Tools

www.leevalley.com

 

[Farmer J.]

Difficult to tell for sure from those photos, but those look like square threads, not acme.

OK. Whilst we're at it here, and if you know about this subject please could you enlighten me and explain a bit about these thread names?
I have a vague notion that what is called 'acme' threads are square shaped and not pointed, so are stronger because they don't try and force the nut apart. I have had a few tries at looking up information but never managed to find facts and with no formal engineering training it's a mystery to me. What does 'acme' mean anyway when used in this sense?

 

[RTM]

Some thread info here

Understanding Screw Threading | ManufacturingTomorrow

While threading is used in multiple industries from large turbine shafts down to small precision metric threads for custom machining projects, each thread type is tooled, both internally and externally, to provide functions for specific applications.

www.manufacturingtomorrow.com

 

[Farmer J.]

Some thread info here

Understanding Screw Threading | ManufacturingTomorrow

While threading is used in multiple industries from large turbine shafts down to small precision metric threads for custom machining projects, each thread type is tooled, both internally and externally, to provide functions for specific applications.

www.manufacturingtomorrow.com

Thanks very much. Nice clear explanation, once again the breadth of knowledge and kindness of members on GJ to share it amazes me.

 

[powerwagon63]

Leg vise screw.

 

[powerwagon63]

A tail vise that goes on the bench end has a longer screw.

 

[TailGunner3000]

OK. Whilst we're at it here, and if you know about this subject please could you enlighten me and explain a bit about these thread names?
I have a vague notion that what is called 'acme' threads are square shaped and not pointed, so are stronger because they don't try and force the nut apart. I have had a few tries at looking up information but never managed to find facts and with no formal engineering training it's a mystery to me. What does 'acme' mean anyway when used in this sense?

Really great video explanation here:

 

[Farmer J.]

Really great video explanation here:

Thank you. I will watch that later after work, for some reason Mrs Farmer J finds it odd if I play videos about threads at 3am.

 

[Ironblock]

Found this in my grandfather's garage. I know it's the drive screw for a woodworking vise but I can't figure out if it's a shoulder vise or tail vise. Can anyone shed some light please

It's called a Woodworking Tail-Vise. I just bought one from Woodcraft. Can be used any number of ways, I've even seen two of them used in tandem.