Wood's Metal

[boater sam]

thanks for that link sam have just ordered a load of 4ba nuts and bolts
Rob T

Glad to help. I forgot Carrs solder, I think they used it on those soldered links on mains transformers that melt on overheat.
I can't remember what they use in oil supply fire shut off valves , it must be similar, maybe a bit higher temperature. If you could find one there should be enough metal for your job. The whole screw thread is designed to melt to let the spring close the needle valve.