3/16" flat bottom holes(shoulders)

[Atlas Knife Company]

How do I drill a flat bottomed hole in metal? I am working on a folder and need a 1/16" through-hole with a 3/16" shoulder. The material is only 1/16" thick, otherwise I wouldn't worry about the angle. If it was wood, I would use a forstner bit. Is there something similar for metal? I have a drill press but not a mill.

The metal being worked is 6al4v if it matters.

 

[richard j]

you need a counterbore with a pilot. i have made them before using a spin fixture on a surface grinder and grinding down the first 1/4" of a drill bit to the pilot hole size. let me know if you cant find one and i'll see if can use my buddys surface grinder to make one.

 

[Salem Straub]

Or you can chuck up the 1/16" bit, push it through the hole to line up the chuck, then with the work and table clamped firmly take the bit out and chuck up a center-cutting 3/16" end mill, run it slow and just push it down to get your shoulder... if the work didn't shift after you lined it up, the center should be good. I do this for corbys since I'm too cheap to get a corby drill/counterbore.

 

[Atlas Knife Company]

Off to ebay to look for some end mills