[FoxCNC1]

Good Morning gentleman,

I have been making regular holes with my CNC machine often times by peck drilling with and end-mill (I know..) or pocketing a hole if it were larger then the endmill.
I am fairly comfortable with that process I guess. However I have never made a counter sunk hole to house hardware because I am unsure of the correct way to do this.

Aside from the CNC tool path which I am guessing is just a simple drill operation, are there specific mills to cut the tapers to match existing hardware that is available?
for instance: https://www.mcmaster.com/#93791a557/=18wpbu1

Or is it a single tool similar to a 90 deg V cutter that just get plunged? Or should be using a center dill? I have a few of those but very small and I don't think those are used for drilling right are they, they are supposed to be for lathe centers (not sure what that is)? Are all Counter Sunk heads 82 degrees?

PS: My CNC Machine has an ER collet

[Jim Dawson]

To countersink holes you use a special bit called a countersink. It is used by plunging into the hole. These come in ''0'' flute, 1 flute, and multi-flute. The ''0'' flute and 1 flute tools are less prone to chatter. Normally used at 1/2 or less of drilling speed and work best with cutting oil. Commonly available in 90, 82, and 60 degree. Metric countersunk fasteners have 90 degree tapers, English screws normally are 82 degrees. I personally like M.A.Ford brand countersinks, they seem to work better than others at least for me.

https://www.mcmaster.com/#countersinks/=18wqoka

https://www.mcmaster.com/#countersinks/=18wqofo

[dertsap]

If your planning to c sink on your cnc then I'd suggest using something like these countersinks which are the least prone to chatter http://www.siteadmincp.com/sites/sit...untersinks.pdf