Funny story,,,,,,
When I made the 4mm and 6mm tube settings I knew nothing about them and couldn't fund any info on the web.I sat for a long time thinking if I really wanted to do this but God hates a coward so off I went!
I checked the size of all the 6 stones with a caliper and choose a drill that was slightly bigger then the stones.I wrapped bezel wire around the 2 different size drills and soldered the joints of the bezel wires.I took what I thought was the appropriate size square wire,made small rings to fit inside of the "bezel tubes" and soldered them inside and flush with the top edges,,,,are we havin fun yet? LOL
If all of the above wasn't difficult enough for me to do I now had to make seats for the stones into that square wire,,,,setting burrs,,,,never heard of them and wouldn't know one if it was sitting in front of me!
I took(I think) a 5/32" and 15/64" drills and ground the cutting edges as close as possible to match the angles of the stones.
When I drilled into the first setting I well knew that the square wire was not "deep" enough so it was back to the drawing board again!
I made 2 sets of the square wire for each setting and soldered the 2 pieces of square wire together to get the depth I needed for the stones.I also used a taller bezel wire to give me a little more room for error.
After getting the square wire soldered into the tubes I had to solder the tubes themselves onto pieces of silver so I had something to hold the tubes for drilling,,,,I learned this while trying to drill the original tubes! LOL
I snipped away some of the silver holding the tubes and carefully sanded the rest off with small 3/4" fine sanding disks in my Foredom.I should add that I have the Foredom drill press.
I had to "play" with the angles inside the settings for a LONG time till I got then as close as possible to match the stones.I epoxied the settings into the guard of the knife I was making and then set the stones using a curved burnishing tool.
A long time after I did this I found that I could have bough tube settings and that there is such a thing as setting burrs! LOL I never even gave it a thought to use heavy walled tubing either! LOL
They didn't come out as good as a jeweler could do but I did do it!

Like I said in a previous post about me making tube settings,,,NEVER AGAIN! LOL
connrock