Curving small flanges for braces on slide tubes, etc.

[arpthark]

I have some smaller mandrels and round steel that works well for forming medium-to-large sized flanges, but I have a few little pull knobs, small braces, and things like that which have small flanges that I would like to get to seat perfectly on rounded slide tubing. I'm having a hard time getting them to behave in a way that doesn't involve accidentally mashing my fingers a few times. Do you have a method for fiddly parts like this?

[MiBrassFS]

Not sure this will help, but I usually use a burnisher and a smaller mandrel, etc. as opposed to tapping them down. I also always try to go slightly past the curve needed so that it’s a nice, tight fit.