Dimples
Jeff,
I think I would use the word "cuts", not flattens to describe what you are doing.
Remember that 0.002 off a 0.025 skin is 8% of the thickness, and this is in an area that has already been thinned by the dimpling action.
I would get better dies, countersinking (cutting) with a deburring tool is somewhat of an uncontrolled process.....
gil in Tucson EAA Tech. Counselor
---------------------------------------------------
A way that you can improve pop-dimples, or any other dimple is to take your deburring tool and spin it around a couple times in the dimple. This flattens the walls of the dimple and makes the rivet sit down in there real nice.
Regards,
__________________
Jeff Orear
RV6A N782P (reserved)
Peshtigo, WI