What is this tool for?

How about Bomb disposal? made of brass for non-magnetic or sparks?

Hello everybody. Yes new member 1st post, hello etc, etc.
I don’t buy the bench clamp. It looks made to slip off and makes the channel in the lower pedestal redundant. The radial grooves are I think air channels from the casting process. I suspect the lower part slides into an aperture and the screw used to compress something to allow fitment, removal or adjustment of some component through the hole. It would have been cheaper stamped from steel and I think it’s brass to be spark proof suggesting fuel or explosive. It may not be a tool for routine use but perhaps for contingency. Extracting a jammed round or link perhaps?

here we go some better pics

Could this be for lining up something like chain links ?

The hexagonal hole might be for a bolt head or similar, to hold the device on a bench, with the screw mechanism operating horizontally, rather than vertically.

Is the bottom flange definitely one piece with the rest? Can I see some silver at that joint?

I was thinking instruments as well but for different reasons. It’s quite small and little force could be used.

could it be to protect the edge of something as it was being rodded or something being threaded in?

Being made of brass, it would be non magnetic, so could possibly be to do with instruments?

paul has some good points , if clamped to a table then whatever may have been in the hole would project horizontaly outward,
I have had a close look at the hole , it is not cleanly machined out at all and although roughly round not hexagonal or other shape, it has a small flange on the side where the grooves are ,
it does not look as if anything was ever permanently fixed in the hole.

The long thread suggests that it had to cope with varying thicknesses such as a bench. However once clamped to the bench only the hex hole is accessible from the grooved side. So clamp to bench, insert something hex shaped and turn item using slots as guides.
The tool is clearly specific to a job and does not look “home” made is it not odd it has no tool number. How can you order one from the stores?

I’d still go for it being a bench clamp but your description of the hole in the side and the radiation slots suggests that whatever it was supporting on a bench is missing. But whatever it was could itself be clamped in several positions located by the radiating slots.

On closer inspection it would seem that hole os hexagonal with grooves radiating from each point. Surely this must have a purpose. Is that a ball swivel on the end of the thread? If so that would need to bear on flattish surface. Maybe there is another part?

It reminds me of a brake caliper piston push back tool. However, the clamp is designed for operation by fingers as it is fitted with knurled knob and not a hexagon for spanner application. Therefore not too much force which fits with being made from brass. Maybe spiral pin or similar insertion.

It looks like a clamp which fixes something to a bench etc. something would have been fitted to it where the hole is I suspect.

Pete

Valve spring compressor?

Yes, I was looking at that hole and the grooves; I agree they must be there for a reason.

Made of brass because it was easier to cast or so that it didn’t damage delicate or precision steel parts?

entirely brass only markings are crown over AM and 1943, the grooves on the back that centre onto the hole look like they are there for a reason.
the bottom plate is not dead flat but slightly raised on each side
being a joiner it made me think along the lines of a specific woodwork related tool but I suppose by 1943 there were fewer wooden components.

No part number I suppose?

Ian I had to chuckle at your answer as I had just screwed it onto my thumb thinking it might be a medical tool, its all brass and the thread is fairly fine so it was never made to exert any great force so perhaps it is something to do with springs as Malcolm suggested?

Is it for extracting secrets? Apply thumb, turn screw etc.