Milling cast aluminum

(Richard Herring ) #1

Newbie here, first post… So my question is, do i need any special bit to mill a cast aluminum plate from an amunition reloading machine a friend of mine has. It’s current thickness is 1.060 inches and he needs it down to .099 inches.

I’m not sure of the exact kind of aluminum and I don’t even know if cast aluminum is any different than say 6061 sheet aluminum or whatever. Like I said, total newb here… Any advice would be very welcome. Thank you.

Also fyi, I’m running a Shapeoko3 xxl with the Dewalt router.

(William Adams) #2

Casting is a process, 6061 is the number of a particular alloy. There’s a bit of discussion on this at:

I being cast ought to make it easier to mill than if it were a forged / tempered sheet, but it being cast means that it may be made up of an alloy which is difficult to machine.

A carbide endmill ought to work fine if it can be machined easily. If it’s a soft, gummy alloy which is difficult to machine, coolant and/or a suitable endmill may help.

(Richard Cournoyer) #3
  1. Buy some ZrN Coated end mills (Bits?)

  2. Advice: Buy a Makita RT0700 Router (runs at 10k, so it produces less heat)

  3. Trust me.

(Richard Herring ) #4

Thank you for all this info! Much appreciated

(Griff Carpenter) #5

Rich, re those coated end mills, one, two or three flutes?

(Richard Cournoyer) #6

Three (3) or as my BIL says, tree flute…

(Michael Ichino) #7

Cast aluminum is usually 356, can be porous, not too gummy and usually small chips. HS 2 flute, TiN coat is OK. Avoid high spindle rpm & heavy feed.