One of the puzzles was from David Pitcher and uses these screws. I'll need to go to a hardware store to get some screws for the other puzzles and it would be nice if I could find an equivalent screw for this puzzle at the same time. Does anyone know what size they are?
I just checked the description for all of his puzzle designs and whenever he doesn't mention M3 screws he links to http://www.hknowstore.com/locale/en-US/item.aspx?corpname=nowstore&itemid=36010da2-4203-4ed6-a641-4a027c0d2642
I have a bunch of those and they are 19mm M3 screws. The battery in my calipers is dead right now and replacement batteries haven't arrived yet so I've used a US Penny (19mm diameter) as a reference:
dayan_screws.png [ 1.02 MiB | Viewed 314 times ]
The steel screw on the right is a standard 20mm M3 screw.
I'm not a fan of the Dayan screws because the head on them is really big and they don't have threading along the whole shaft. If you are going to use different screws, 20mm M3 screws with a "Pan head" will do just fine.