I make camera and optical parts also.I also have the same problem. I cut a 45
deg. chamfer a little deeper than the thread deepth .A .75 mm thread deepth is
..75 x.03937 x .61343 =.0181 inch deep.I would cut the chamfer .025 and then
thread it.Using a full profile insert .Then chamfer it again and then make
another pass with the threading tool.It only adds a few seconds to the
program.But this does'nt get rid of the burr entirely.So i just lightly sand
the bur with 400 grit sand paper buy hand while the next part is turning it
only takes a few seconds but it does get old after a few hundred .