A couple of people have been asking me to make some pieces similar to those from the Staffordshire Hoard, so I decided while I had nothing to do at work for a while (rare occurrence!!) that I would try and make a simple beading file as described by Theophilus. After a few attempts I was able to make consistent .5 mm beads. Making the tool larger and with a handle(s) would make the work a lot easier on the fingers! This was done by rolling the wire on a hardwood surface and forming each bead individually. I found that it was best to do this in 2 or 3 stages, annealing the wire in between. Trying to go to far in one go just would cut the wire. I used sterling wire for this, I imagine fine silver and high karat gold would be easier to do this with. The beads ended up with a distinctive line around the center of each one as described by some experimental archaeologists who tried to replicate the techniques of creating similar pieces, I think they were trying to differentiate beaded wires made by this technique and those made using an organarium.(....I have the articles somewhere, or links to them if anyone wants me search of them)
Maybe this weekend I will make some better tools and try to get the beads down to around .2 mm like some of the stuff I have been looking at :) Still have to make a better organarium someday.