Surprising Results of Endmill Benchmark Test

I posted a couple weeks ago about upgrading our endmill inventory asking for recommendations. I decided to do a benchmark test on some of the recommendations I got from that post.

My testing procedure was to try a variety of cut types including profile, slot, and HSM at a constant RPM, while achieving the same spindle load on each tool and compare the various feedrates each tool was able to sustain.

My Machine: HAAS Mini-mill, 6000RPM, CAT40 spindle. I know this was not the ideal machine, and certainly not as powerful as those videos you see on youtube, but it was all that was available at the time, and I think it worked out ok.

Test Tool: 1/2 diam x 1.25" loc 3 flute, finish endmill 1.50" extension from tool holder
1) Accupro 37 degree helix Zrn coating manf# 65250193
2) Niagara 45 degree helix TiCN coating manf# n61655
3) SGS s-carb series, 38 degree helix TiB2 coating manf# 34740
all tools were placed in ER32 collet holders, I did not have time to check the runout of each one

Material: 6061 extruded alum bar stock, 4.00 X 6.00 X 8.00

I. Profile Cut, 25% radial, 125% doc (.125 X .625) 6000 rpm
A. Accupro, maintained 80% spindle load at 78ipm, peaked at 130% spindle load at 84ipm
B. Niagara, maintained 80% spindle load at 55.25ipm, peaked at 130% spindle load at 62.4ipm
C. SGS, maintained 80% spindle load at 65ipm, peaked at 130% spindle load at 71.5ipm
*winner: Accupro, 6.094 in3/m @ %80 load

II. Slot Cut, 50% doc (.25 X .50) 6000 rpm
A. Accupro, maintained 60% spindle load at 30.42ipm
B. Niagara, maintained 60% spindle load at 14.04ipm
C. SGS, maintained 60% spindle load at 23.4ipm
*winner: Accupro, 3.80 in3/m @ %60 load

III. HSM/Dynamic cut, 10% radial, 125% doc (.05 X .625) 6000 rpm
A. Accupro, maintained 60% spindle load at 160ipm
B. Niagara, maintained 60% spindle load at 40ipm
C. SGS, maintained 60% spindle load at 45.5ipm
*winner: Accupro, 5.00 in3/m @ %60 load

It was a huge suprise to me that the Accupro brand beat out the others, as they are about $20 cheaper. Let me know what you think. I would appreciate any feedback about if my method was flawed or if I am overlooking something or not factoring in something. Thanks!

They all have different Helix angles and coatings. Yet still kind of surprised at Accucrap endmills.

The test doesn't tell you that the Accupro is better, it's telling you that the ZrN coating is better for Aluminum.
For a better test, you need the same coating and the same helix from the 3 manufacturers. If the Accupro still beats them, THEN i'll be impressed.

Include this one in your tests, I have used these a LOT with great results: square end variable flute end mill for aluminum

Just a thought,

The coating on the SGS, I wasn't familiar with it, so I looked it up... SGS Tool Company- A Leading Manufacturer of Round, Solid Carbide Cutting Tool Technology.

Our toughest coating ever, recommended for use with silicon
aluminum alloys and titanium alloys.
Recommended for applications in high silicon aluminum alloys
and titanium alloys.

Click to expand...

Oxidation Temperature:
850°C – 1562°F

Coefficient of Friction:
.45

Thickness:
1 – 2 Microns
(based on tool diameter)

Click to expand...

I'm thinking you weren't getting hot enough in the cut for the coating to start working its magic, I'd be interested
to see the results from the same endmill with a lower temp coating, or no coating at all..

Bobw said:

Just a thought,

The coating on the SGS, I wasn't familiar with it, so I looked it up... SGS Tool Company- A Leading Manufacturer of Round, Solid Carbide Cutting Tool Technology.






I'm thinking you weren't getting hot enough in the cut for the coating to start working its magic, I'd be interested
to see the results from the same endmill with a lower temp coating, or no coating at all..

Click to expand...

Wouldn't that coating be better suited for an aluminum with higher silicon content than a 6000 series aluminum? Or is 6061 considered a high Si content alum?

I forgot to mention in the OP, after testing, the Niagara was already exhibiting significant wear on the corners, and the SGS was just barely starting to show corner wear. The Accupro had none

Great test! My guess is the coating and helix angle made Accupro the winner. TiCn is more for high silicon aluminum alloys like cast Aluminum and the 45 deg helix on the Niagara probably had a little bit of chip build up. Something else to consider is if all the coatings were the same Accupro might be good this time but you might get a whole different end mill next time you order. They are manufactured all over the world.

My biggest surprise was the Niagara, I have used them alot in the past for 304SS, but in this scenario they're supposed "specialty" cutter for alum performed terribly.

great to be doing a test; must keep the EM makers honest!

Benchmark brand makes some real nice Alum cutters, FWIW.

more tests please!

I'd like to do another test in the near future, but have to find some time. Let's line up 3 more contenders, who would you recommend?

Helical solutions, they are our go to for endmills.

Find High Performance End Mills and Cutting Tools at Helical Solutions

CGC Tools - Products

Products

I recently got a 3/16" end mill for aluminum from McMaster since I was ordering from them anyway. Turns out it was a Niagara. My thoughts about it are in line with your test. Accupros cut well but are not the best carbide. My benchmark end mills for aluminum are Destiny Tool's 3 flute Viper and if you want to reduce spindle load/ cutter force then it is the 3 flute Diamond mills, all with the Stealth coating. They also last a very long time and the sharp corners don't chip off like some other end mills. I would add a Destiny Viper mill to your test but try including tool life, if possible.

Not surprised at all.
A tool test is spindle load not total life? Generally on short term runs this is the sign of low life. You can build for low initial power or long life. This is an easy trade off.
Helix is one thing, but flute shape counts too. Helix changes the the direction across the shear changing the top rake angle.
TiB2 while awesome pretty (it looks like chrome plated) does not need temp to work. It does not like real high silicon content so that one seems a bit weird to me.
What works for you ... works. Low initial power often means less total cutting time but this is not always true.

If you run all these endmills into the ground in your shop are the results the same?
Accupros are not bad tools.
Bob

CarbideBob said:

Not surprised at all.
A tool test is spindle load not total life? Generally on short term runs this is the sign of low life. You can build for low initial power or long life. This is an easy trade off.
Helix is one thing, but flute shape counts too. Helix changes the the direction across the shear changing the top rake angle.
TiB2 while awesome pretty (it looks like chrome plated) does not need temp to work. It does not like real high silicon content so that one seems a bit weird to me.
What works for you ... works. Low initial power often means less total cutting time but this is not always true.

If you run all these endmills into the ground in your shop are the results the same?
Accupros are not bad tools.
Bob

Click to expand...

Hi Bob,

Unfortunately in our case, only time will tell as far as the overall tool life. I would love to just run each one for a couple hours on a big hunk of material, but don't have the time or resources for that. But yes, it could be that after a short amount of time in cut, the accupro might end up having to back off to the same Feedrates as the SGS.

Get a hold of gwshultz they will send you a free alumigator end mill high ramp angle 9degrees I feed them 420 ipm at 12 k rpms full depth .07 step over on 3/4 zrn coated last great

D Nelson said:

Get a hold of gwshultz they will send you a free alumigator end mill high ramp angle 9degrees I feed them 420 ipm at 12 k rpms full depth .07 step over on 3/4 zrn coated last great

Click to expand...

I agree with this. I have seem my 1" with .125 rad zrn last literally 6 weeks hogging 6hrs per day on a large horizontal in 7050 Al. Ran so long it was an event to finally swap it.

Yeah and you can damn near straight plunge through a wheel they will eat they have a very aggressive tip gash but you can't get anybody to try them and are priced right to boot I am sold on them we use the .125 rad. Also

We tested over 30 brands of roughing endmills for aluminum over the last 5 years. Swiftcarb is good... the ART endmills from GW Schultz are the best we have found. They can ramp at 45 degrees and get about 4-5X the tool life of what we did with GW's RFA series. The ART have a truncated radius where the RFA's had sharp corners.

If I wanted to test the handling capabilities of tires, I would not do it in a Yaris. 6,000 RPM is not much of a testing methodology for aluminum cutting end mills.