Unknown machinist's vise - info requested

Out of curiousity I am wondering if anyone can help me identify which factory produced this machinist's vise that I just purchased at this morning's flea market.

The sliding jaw casting is bolted to a solid 40mm diameter bar and opens out to something just over 8.5 inches. The screw mechanism is protected at the rear with a bolted-on housing.

I suspect that it was produced in either Britain or America as the hardware takes inch-size allen wrenches. Other than that there are no identification marks or numbers to be found anywhere.

I showed these pictures to two of my friends this morning, explaining at the same time about how robust the vise was as well as the lack of identification.

My first friend offered the suggestion that it might be ex-military hardware. My other friend was of the opinion that it might have been a vise for use on a ship where the relatively compact castings would offer a bit of a weight savings.

Would a ship need to save weight?

Good observation there, Ian. But I'm just as uncertain as you are on that point. Perhaps on a smaller vessel ? Submarine?

Doesn't really help identification but if it was military wouldn't it have broad arrow markings on it at least if made within the last seventy or eighty years. Also the moving jaw looks almost identical to a Record Auto Mechanics vice that I once owned. And wished I still did own!

Phil

Those record auto vices come up semi-frequently on ebay in all three sizes (imp, 74, and 75) ... I've bought a few for various tasks through the site.

Just a little extra information about the construction of that vise.

In the intervening time between this and my previous post I've been cruising the internet looking at pictures of old bench vises and have found nothing quite like this old thing.

I thought the grip range would be up to something like 210 mm, but the real measure is 180 mm. Still quite fine for me.

My first impression was that the top cylindrical section was a protective housing around the screw which worked in threading cut into the wall of the casting. I tried to unscrew the bolts holding it to the rear of the casting and realized it was locked to and moving with the threaded rod. In fact, that cylinder on top is also solid, but bored out and threaded internally. It probably has a section that extends beyond the rear flange and fits into a bored socket at the rear of the housing. I didn't bother taking it all the way off, but snugged the bolts back down tight and unscrewed the vise far enough that I could give the threaded rod a good coating of graphite grease.

The design is so arranged that when opening the vise no threaded portion of the shaft appears until the vise has been opened to at least about 8 or 9 centimeters. The shaft that does show normally is a very close fit in the hole bored into the casting, no doubt preventing the ingress of work swarf and contributing to little wear and almost zero play in the action of the thread when turned.

In the intervening time between now and my previous post I've been cruising the internet looking at pictures of old bench vises and have still found nothing quite like this old thing.