View Full Version : Annular Cutter RPM

03-09-2015, 08:57 PM
Tomorrow I should be getting the 1-1/16" annular cutter that you guys recommended for drilling all the holes for my new press Im building. The metal is 1" thick. What RPM should I be running it? I will be using my Acer Mill. thanks Paul

03-09-2015, 09:03 PM
Hougen has a speed/feed calculator on their website and offers technical support (things like tooth count and feed speeds play a role)

03-09-2015, 09:07 PM
yes, go to Hougen.. and use coolant.

03-09-2015, 09:26 PM
Same as turning.

If in steel, 100 fpm is pleanty fast. A 1-1/16 cutter has a diameter of about 1/3 foot, so 300 rpm would be fast ...

Use coolant or even sulfur oil. Best tip? Drill a small "chip breaker hole" just at the anular cutter perphery. But not quite through the work. fill the hole with cutting oil or wax. That way, the chip breaks every rev, and you don't run dry of cutting fluid. Additional fluid is still a good idea!

Ohio Mike
03-09-2015, 09:27 PM
Cutter RPM = (SFM x 12)/(3.14 x D) where D is cutter diameter.

SFM should be less than 100 for a HSS cutter in mild steel much like a lathe op. I'd calculate the values at both 50 and 100 SFM and find a speed on your machine about half way and see how it feels. Use copious amounts of coolant.

03-09-2015, 10:05 PM
Annular cutter details as well as appropriate drills are here:


Check the spindle speed of the magnetic drill for a good guide as to the speed/s to use - example: