I was taken by surprise during my simple addition of making the M2.5-0.45 and M3-0.5 thread gages (see the second page to http://www.homemadetools.net/forum/t...-caddy-55964-2 ) when I discovered the die diameters for cutting the treads were 20 mm and not 13/16" in diameters. I bought the dies years ago from Enco (now part of MSC) and never thought to check the diameters until I started using them. I do not have any die stocks or a lathe die stock for the 20 mm diameter dies.
I made a simple 20 mm ID sleeve from 1" dia. stainless steel 303 solid rod, bored to 20.05 mm ID, with three pass-through screw holding holes for holding the dies from the set screws in a 1" (25.4 mm) tailstock die holder.
The typical 13/16" dies are 0.8125" in diameter and the 20 mm dies are 0.7874" in diameter. Very easy to not notice the difference in diameters unless I laid one die on top of the other and looked closely to see the difference. Now that I know the difference I have found through the Internet several designs of the 20 mm diameter die stock holders for dies typically in the M2.5 to M6 ranges.
THe following are the construction steps.
THank you for looking,