John in NM
Built a bed with bed bolts, but I was too cheap to buy actual bed bolts, used regular 6" bolts with a big shiny hex head. I made some rosewood caps using one of those chattering fly cutter like rosette things, with a shallow hole in the back for a dowel. The dowel sticks into the bolt head hole and has a magnet let into it - get the dowel length just so and the magnet holds the cap over the bolt head.

Of course such a thing would fall off the bench every time you whacked something with a mallet but maybe you can improve on the idea