View Full Version : Recommendation for End Milling Aluminum

02-17-2011, 10:50 PM
Good Evening,

I'm looking for recommendations for an endmill for aluminum.

Plate aluminum-- 1" thick

Machine-- Jet JM -15 ( Mill Drill )

The plate is saw cut now. Looking to remove .125" to reduce width

I am open to roughing and finishing options.

Coatings ?

Cutting fluids ?

Thanks, Ron

02-17-2011, 11:59 PM
For cutting Aluminum, you'll need a high-helix, 2-Flute endmill for best results.
Get the largest diameter your mill can hold, for rigidity.
Like this:
A 1/2" endmill has 1-1/4 of flute length. That'll be enough to side-mill your 1" plate.
The 1/2" endmill is only $11.00 plus shipping.
Here's a link for ordering online:
Victor Machinery (http://www.victornet.com/subdepartments/End-Mills-for-Aluminum-high-helix/1560.html)

02-18-2011, 01:16 AM
I like the variable 3 flute ZrN coated carbide bits from Lake Shore Carbide. Crazy sharp, plow through aluminum, and run real smooth. Great on manual or CNC mills. I had used the same 1/2 end mill for over 2 years till I chipped out a flute. Amazing, it still cuts nice.


Also pick up their spotting drills. Real nice.

02-18-2011, 01:26 AM
While in general you want a 2 or 3 flute endmill for work in aluminum for chip clearance when end milling, and when in slots or other confined areas, When side milling the edges of a workpeice, Chip clearance is hardly a consern, And you can go with 4 or even 6 flute cutters to improve overall feed rate.

0.125" isent really enough to bother with roughing and finishing tools changes.

02-18-2011, 05:06 PM
I do a lot of work with aluminium 6082. Although those high helix are recommended they need more pressure on the actual job creating quicker heat build up plus leave chaffs marks unless taking a fine cut.

I also use a lot of three but mostly four flute for side cutting, just get the feed right. Current favourite ITC savage.
Think his machine would flex before the cutter so max 1/2" dia long. Side faced 32mm deep easilly 1/8" either side with a 9mm ITC 4 flute no pick up mostly dry.

08-03-2011, 09:09 PM
I don't have a mill/drill but I can comment that even a sloppy half worn out bridgeport [like mine] can take that amount of Aluminum off in 2-3 passes if you use a 3/4" 4 flute cutter.

If you don't have a 3/4" R8 collet (or MT3) and a 3/4" endmill you should get one, they are much more rigid than smaller cutters. I have a few of these size endmills and they have become my go-to cutter for this type of thing.

brush on some oil to keep the aluminum from galling to your tool.

Paul Alciatore
08-03-2011, 09:16 PM
There are already some good end mill recomendatons. As for cutting fluid, I always use WD-40 for aluminum.

08-04-2011, 05:17 AM
I recently did a job involving a very large piece of 1" Al. plate. I used a 3/4 dia. X 2" long two flute end mill with a 3:1 mix of kerosene and oil for coolant/lubricant. Worked fine. If you are doing pockets or deep slots rig up an air line to a regulator and position an air flow to the slot or pocket to blow chips out. Often times this alone with a little bit of brushed on lubricant will be all you will need. As someone stated above I would not run dry because softer aluminum is notorious for caking onto the cutting edge and diminishing the efficiency of the cut. If you are milling something like 6061-T6 (a harder aluminum) you'll find that caking is far less severe but you should still apply some sort of lubricant though you may find that you can get away with doing it more sparingly.

08-04-2011, 07:12 AM
I've got these HSS-PM (powdered metal) 3-flute TiCN-coated end mills from Niagara, the 3 on the far right. The package says they are for aluminum.


My God those things kick butt in aluminum on a 1HP Bridgeport! Just the sound of the cutters in action is sweet.

For a 1/8" width of cut at the 1" cutting length (or depth of cut), you should consider getting the largest diameter 30 to 45 helix HSS cutter you can afford. This will afford chip-thinning action and you can successfully (but carefully) climb with it for a smooth finish.

08-04-2011, 10:02 AM
The Niagra ones for Aluminum have a 37 degree helix. Most regular endmills have a 30 degree. I use the 2 and 3 flute Niagra ones a lot and it's amazing the difference that 7 degrees makes. They sail through aluminum effortlessly and give a clean smooth finish. You do have to use cutting oil or coolant to keep the alum. from sticking to them. That is the same with any end mill. I use either Tap Magic for Aluminum or water based machine coolant.

08-04-2011, 11:09 AM
Can't comment on the mill cutter ( I too have a Jet MD that does fine with AL, four flute for nice edges, two flute on slots), but for lubricant I use a few drops of AlumiTap tapping fluid. You need very little of it so it doesn't make a big mess, and it leaves a very nice finish (assuming speeds/ feeds are OK).

2 cents please.

08-04-2011, 11:37 AM
Well since everyone is tossing in thier favourite 2 cents worth here is my go to cutter for AL:


Used with a dribble of Relton A9 cutting oil for aluminum

08-04-2011, 12:25 PM
The most important thing for cutting aluminum is to use a BRAND NEW razor sharp end mill. I use a 4 flute end mill with Kerosene cutting fluid.