Well its to make a projector ceiling bracket. The ceiling in my cinema is very low and I can't find a bracket thats short enough so the projector don't get in the way of peoples view when there sitting on the raised seating. This "grub screw" will just stop the brackets adjustments from moving from the vibrations of the sound. the bracket will be painted black but ill probably make it out of Ash, Oak or Beech, depending on what I find in the wood store. The grub screw will go through the face of a round plate about 15mm thick and onto another round plate but there will be room for the screw to poke out a bit.
The reason for hex is so I can use the short section of a hex key to turn the grub as I wouldn't have room to get a screw driver in there. I have an hex key shaped tool but the short side is a philips head so I could use one with a Phillips head but not slotted.
I would prefer the grub to sink rather then poke out but its not to much bother if it pokes out. The round plate will be over 100mm in diameter so an insert would have room however the grub location will be way off centre so a lath turned thread would be out of the question.
Roger, if you think the ones you have would do the job then yes please.
JasonB, That my friend may just work a treat.
Thanks all.