NOGA Reversible Countersink
That burr raised by drilling or tapping into an internal shaft, hole or cylinder? THIS IS THE TOOL for you! Pushing the bottom straightens out the blade so that the tool can slide through the hole, then the blade pivots out to debur the hole!
The RC1000 does 0.12″ to 0.21″ (3 – 5.5mm). The RC2000 does 0.197″ to 0.394″ (5-10mm)