Best CNC Router bit for 3/4" MDF?

Router bit? Are you wanting to cut it or do an edge profile?

Carbide is the way to go as MDF has some hard resin bonding all that sawdust together 8^)

@splintergroup I updated the title – I’m specifically looking for a CNC router bit.

I’m not sure about the best but a Vortex 840 (3/8” 1-flute upcut) is pretty good. That will handle full depth cuts in 3/4” MDF at 300+ ipm feedrates assuming your machine is up to the task.

18-24k RPM is too fast for 300ipm if using a 2-flute bit. That’s why I recommend the 1-flute. 300ipm is close to the recommended feed rate for that bit.

-- See my work at http://altaredesign.com

@jaaune what RPM would you run a 2 flute but at?

That’s a complicated subject since it depends upon the spindle, machine rigidity, material type, hold down strength and various other factors.

Start by looking at the Vortex chipload chart to see what the bit manufacturer recommends. They recommend around 720ipm for a 2-flute, 3/8” diameter bit.

Vortex Chipload Chart

That’s the ideal for bit life but not always achievable depending upon the factors mentioned earlier. With our router, we’d probably run about 17,500RPM at 250ipm because the spindle and steppers can’t do much better than that which means our machine can’t get much benefit from larger diameter, 2-flute bits.

-- See my work at http://altaredesign.com