# Carbide Inserts - Face Mill Cutter



## Franko (Mar 28, 2015)

I'm looking to purchase a face mill cutter. Most come with inserts designated for steel.
I work mostly with aluminum, but occasionally mill some steel. 
The inserts are pretty costy, so I'll probably have settle with one type for while.

What are the differences between inserts made for aluminum and steel? 
What ugliness results from using one to cut the other?
How about Mitsubishi round inserts?

and...

Is a face mill cutter good for whittling down stock or is there a better option? 
It took me more than 2 hours last night to mill down a 1.5" aluminum rod to a 1.1" square using a .75" end mill making two or three .020 passes on each quill adjustment.

I'd also be interested in any suggestions for a good (reasonable) source for a R8 7/16 face mill cutter. I've spotted a couple on eBay. Decent looking 2" tools seem to be going for about $100 - $130 shipped.
My mill is a bench top (not a mini mill) and probably isn't up to anything much larger, unless I'm wrong.

This one looks decent.

http://www.ebay.com/itm/300946022960?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT


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## Ken_Shea (Mar 28, 2015)

Franko,
As you likely know insert selection can be very confusing to say the least, this is especially true when you don't work with them on a daily, consequently, my statements are at such a basic level in my shop environment and by no means the last word.

Since that tool uses basic inserts the difference is likely that Aluminum cutting inserts will leave a better finish having a sharper edge then the steel cutting, this edge will dull rather quickly and more prone to chipping when used on steel. A basic steel cutting inserts will cut aluminum just fine, just not as smooth a finish as with the aluminum cutting, still, they leave a very acceptable finish I've found. That said, they make both for a reason and swapping will cut the life and/or performance of each but it's done all the time in a home shop, it's just not ideal. These new high tech performance inserts with special coatings can be very particular in operation.

Another option, you can make a fly cutter of almost any size suitable to your equipment pretty easily and use HSS self ground cutters, these can leave a beautiful finish on both steel and aluminum.

Face mills and/or fly cutters are not heavy cutters nor is a small bench top mill, some times you just have to live with it although almost always, performance improvements are there with attention to cutting factors. One big mistake I read about is running too slow a RPM, with aluminum you can almost always run full RPM with appropriate smaller end mills 1/2 or smaller and 2/3 flutes

This is one of those threads where there is no good place to stop talking with SOOOOO many variable in play.


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## Franko (Mar 28, 2015)

Thanks, Ken. Sharper finer edge. That makes sense.

What I was hoping is that a face mill cutter is a better tool for hogging off a lot of material and would be capable of taking deeper cuts than a fly cutter whacking on the edges of the part.


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## pineyfolks (Mar 28, 2015)

I've seen a lot of face mills that looked to be a great deal until I priced the inserts. If you use inserts on your lathe maybe you could make a fly cutter using the same toolholder.


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## Cobra (Mar 28, 2015)

My facemill is more rigid than my fly cutters so will take a deeper cut but the real advantage seems to be the feed rate. 
Because of the multiple cutters on the facemill, you can feed faster and still keep the same load on the cutting tool. 
As noted above, I just use the one set of inserts for all materials.   Seems to work fine for me.


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## Franko (Mar 28, 2015)

Thanks, Bill, Jim.

The face mill I'm watching on eBay comes with 10 rectangular inserts. They look like they have different profiles on opposing corners but since the inserts are rectangular, so I suppose there are only 2 usable cutting corners. The inserts are TIN coated carbide. I'm not sure that I get why there is any advantage in coating a carbide tool with TIN.

It is only $120 shipped from Hong Kong, but it looks decently made with good finish.


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## aliva (Mar 28, 2015)

If you intend to remove a lot of stock, I've used a roughing end mill first, then switch to a face mill, or fly cutter, for the finishing passes.
Better yet, if you can band saw most of the stock first you could save a lot of time and effort.


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## Franko (Mar 28, 2015)

Is the end of a roughing end mill any different from a normal end mill?

I generally try to cut work pieces as close as I can to avoid have to mill any more than I have to, but sometimes the blank needs to be very symmetrical to achieve the end result. What got me thinking of this is a project I did Thursday, where I had to cut .255 off four sides of a round rod, so it was cut and turn, rinse and repeat four times.


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## Cobra (Mar 28, 2015)

The coating is not TIN, but TiN(TitaniumNitride), a ceramic that is vapor deposited on the surface of the carbide. It dramatically extends the life of the cutters by increasing the hardness of the cutter surface and increasing the lubricity of the surface.
I picked up two 3 inch facemills from CDCO (one 75 degree, one 90 degree) for about $65 a piece and an arbor for about $25.  They have worked well for me.  One of them uses triangular inserts, the other is square.  Not cheap for the inserts but the do last well.


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## JimDawson (Mar 28, 2015)

Franko said:


> Is the end of a roughing end mill any different from a normal end mill?



From a functional standpoint, not really.  The tooth shape is a bit is a bit rounded as opposed to a sharp corner in all but finishing roughers which do have a sharp corner.


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## 18w (Mar 28, 2015)

I won't offer up anything useful regarding face mills other than to say if you are only taking .020" passes on aluminum with a 3/4 endmill you aren't even beginning to use the capacity of your mill. Even a small mill should be able to take much deeper cuts. Fly cutters are excellent for finish and larger widths of cut. Some face mills perform the same task while others can also hog material as well as finish but a large dia. face mill requires some h.p. to take deeper cuts. If you just want to remove more material, look in to a 3/4" or 1" hss rougher end mill and experiment with your machine as to how hard you can push it. Lots of folks have face mills, as do I, but insert tooling that requires multiple inserts can use up a tooling budget really fast and if you aren't using it to its full potential, ie. faster feeds and doc, may not be the best choice. IMHO, your mileage may vary.

Darrell


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## Franko (Mar 28, 2015)

Thanks Darrell. 
I recently adjusted the ways to tighten things on that mill so I think everything is tight enough, but I felt like I was pushing as much cut as I could. Any deeper and the mill was starting to shake, especially as the bit crossed over the edge at the end of the pass. I was running the .75" end mill at about 1000 rpm. It is possible I don't have the column ways as tight as they could be. I'll look into that.

One problem I've seen taking deep cuts on aluminum is the cutting edge tends to gum up.

In my perusing face mills, I noticed some one to two inch carbide insert end mills that look like they may be good for removing more material. They use more standard inserts and cost significantly less than the face mills I've seen. MCSC had a 1" one set of 3 they called "The Little Hogger." It looks like they use fairly standard inserts, round, 3-sided and square.


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## Ken_Shea (Mar 28, 2015)

Franko,
1000 is too slow, you should be able to run that 3/4" at 3000rpm if you have that available, that should smooth things up and also allow you to take a deeper cut.

I've never used it but others say WD-40 makes great lubricant for aluminum.
Soft aluminum can be real gummy to machine and lead to that build up you mentioned, WD-40 should help there.

3/4" and .020 as 18w pointed out is not optimum by any means.


Ken


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## Franko (Mar 28, 2015)

I will give that a try, Ken. Thanks. I think 1750 is its top speed.


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## kwilliam (Mar 28, 2015)

Also remember with 4 cutting edges you need 4 times the HP.

I have found even the plain triangular inserts give a great finish on Aluminium - as long as the have the "wiper"

The plain triangular inserts are also very robust


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## 18w (Mar 28, 2015)

+1 on what Ken said.Put it in top speed, spray with wd40 and let her rip. At 1750 rpm with a .750 endmill, that is about 343 sfm. Auminum cutting rates call for about 300 to 600 sfm in hss. Also in aluminum using a hss end mill 2 flute doesn't load up like a 4 flute will. Play with the feed rate also.

Darrell


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## Ken_Shea (Mar 28, 2015)

Back to that Face mill, you won't regret having it if you decide to get one, run a 2" at your full RPM also in any aluminum and around 700rpm in mild steel, I've been kicking around getting a larger one myself as well.


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## Ken_Shea (Mar 28, 2015)

kwilliam said:


> Also remember with 4 cutting edges you need 4 times the HP.



kwilliam,
That's a new one to me and does not bear out in checking required HP in relation to flute count, some increase but it's very minor, almost moot.


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## 18w (Mar 28, 2015)

kwilliam said:


> Also remember with 4 cutting edges you need 4 times the HP.
> 
> I have found even the plain triangular inserts give a great finish on Aluminium - as long as the have the "wiper"
> 
> The plain triangular inserts are also very robust





Ken_Shea said:


> kwilliam,
> That's a new one to me and does not bear out in checking required HP in relation to flute count, some increase but it's very minor, almost moot.



 Ken is correct, facemill geometry governs hp requirements more so than number of inserts. http://www.glacern.com/fm45 shows a face mill with low hp requirements. It is all in how thin a chip is formed at the insert that makes some face mills more suitable. Yes there is some increase in hp requirements involving chip load, feed, rpm and number of inserts. If it took four times the hp even my Bridgeport would be inadequate and it does just fine with multiple insert mills but I am running a Glacern like the link I provided.

Darrell


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## Bill C. (Mar 28, 2015)

Franko said:


> Thanks, Ken. Sharper finer edge. That makes sense.
> 
> What I was hoping is that a face mill cutter is a better tool for hogging off a lot of material and would be capable of taking deeper cuts than a fly cutter whacking on the edges of the part.




Face endmills can really hog off the metal.  I used them on a horizontal milling machine to square up plate stock.  They do a quick job.


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## Ken_Shea (Mar 28, 2015)

Hogging is kinda a relative term and subject to many variables that can drastically reduce material removal rate.
Most of the smaller bench top you are not going to be doing any hogging and increased material rates are increased mostly by attention to set up, feed and speeds, cutter and cutter quality.

Every single machine out there has it's limits, we just have to work around/with them efficiently.

Seems my 2.5 face mill has a max DOC of .200in which I never use.
My normal course for if large amounts of material are needing removed is first, find material that is dimensionally closer 
Next is a carbide rougher to less then finish depth by about .015 then face mill that.
That is using CNC, for a manual machine I likely would just face mill and repeat as needed to depth.
Some of these high end face mills can absolutely fly through material, I have to rely on something of less quality.

Franko,
Work towards getting a 3 Fl variable helix coated for aluminum cutting rougher, don't let the word rougher fool you, they can leave a very nice finish, you'll love it, after 1/2" they get scary pricey though.
This is where my last one came from after snapping my other one 
http://www.lakeshorecarbide.com/standardlengthcornerradiusroughfinishgeometry.aspx


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## Bill C. (Mar 28, 2015)

You are correct, I forgot about the size of the milling machine.  I have used them on BP's but they were smaller in diameter used to bring material down to the correct dimensions.  Thanks for pointing this out.


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## 18w (Mar 28, 2015)

Bill C. said:


> You are correct, I forgot about the size of the milling machine.  I have used them on BP's but they were smaller in diameter used to bring material down to the correct dimensions.  Thanks for pointing this out.



Said by the man with a horizontal mill. Like Crocodile Dundee...."That's not a mill THIS IS A MILL!"


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## Bill C. (Mar 28, 2015)

18w said:


> Said by the man with a horizontal mill. Like Crocodile Dundee...."That's not a mill THIS IS A MILL!"




She was a beast for sure.  It was shame they closed my apprenticeship program before graduation.  That was the last time I set up and used one.  None of the repair departments had one.  We made some much production tooling for manufacturing in the training shop.  About all I did in the repair area was tear down dies and repair die sections or replace punches.  Those were good times before the shut down. (1972-1982)


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## Bill C. (Mar 28, 2015)

Bill C. said:


> She was a beast for sure.  It was shame they closed my apprenticeship program before graduation.  That was the last time I set up and used one.  None of the repair departments had one.  We made some much production tooling for manufacturing in the training shop.  About all I did in the repair area was tear down dies and repair die sections or replace punches.  Those were good times before the shut down. (1979-1982)


  (1979 - 1982)


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## Franko (Mar 28, 2015)

Specs on my mill say it's max spindle speed is 1750 rpm. When I turn it up all the way the tach reads 2000.

Don't be afraid of insulting my knowledge about machining. I'm eager to learn. I'm totally self-taught and have never seen anyone's but my mill and lathe operate, except on tv's _How it's Made_, but those machines are automated, huge, powerful and very fast. My tendency has been to proceed cautiously.

A whole new world has opened up. I tried the higher speed and by golly, it works and the world is once again spinning on greased gears!

I feel like the guy who purchased a chain saw that the salesman promised would cut 3 cords a day.
The next day he limped back to the store and said the best he could cut after the hardest day's work in his life was half a rick.
The salesman checked the chain saw to see if it was working properly,
primed it,
pulled the starter cord
_varoom_! it roared to life.

The guy jumped back and cried, "What's that noise?!!"


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## 18w (Mar 29, 2015)




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## Franko (Mar 30, 2015)

I made a part today running a .75" end mill at 1800 rpm (fast as it would go today). I milled a half inch off the edges of a section of 2" x 2" x .5" aluminum bar to 1.5" in two passes per side, taking .20" and finishing with .05 cuts. It felt like I could have taken more. Then then I cut a .3' x .5" rabbit in all four sides in one pass to make a cap for a section of 1.5" aluminum tube.

My mill has never run that smoothly. I've never taken cuts that deep before and it whizzed through the aluminum like it was wax. My mills have always drug on the back side from deflection at the slower spindle speeds I was running.

Again many thanks to you guys for the advise and help.

I ordered a insert facing mill from CDCO this weekend. It is a two inch three insert mill with a .75 straight shank and uses fairly inexpensive TPG32 inserts. I ordered some TiN coated inserts on eBay for it, as it comes with regular carbide.


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## Ken_Shea (Mar 30, 2015)

That's real good news Franko, RPM is a big friend for aluminum.
You will get a lot of use from your new face mill.


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## Franko (Mar 31, 2015)

Ken_Shea said:


> Work towards getting a 3 Fl variable helix coated for aluminum cutting rougher, don't let the word rougher fool you, they can leave a very nice finish, you'll love it, after 1/2" they get scary pricey though.
> This is where my last one came from after snapping my other one
> http://www.lakeshorecarbide.com/standardlengthcornerradiusroughfinishgeometry.aspx



Ken, I'm not sure I see what distinguishes a variable helix (flute) end mill. What's different with a variable helix and a regular end mill? They appear very similar to the end mills I've been using, with maybe a tighter spiral. I searched the Googles but found no description or education on them.

David convinced me I should try some spiral taps so I ordered a basic assortment.


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## Ken_Shea (Mar 31, 2015)

Franko,
I've confused you with the use of variable Helix, my bad  the end mills linked too are variable flute although there are variable helix end mills.
Not to be confused with a variable helix, a variable flute in the 3 fl example would have the flutes not indexed at exactly 120º but at varying degrees of index. This breaks up the harmonics/vibrations, offers a smoother cut and allows a more aggressive feed, if I may coin a phrase from Martha Stewart, "it's a good thing" 


Ken


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## Franko (Mar 31, 2015)

It's like shooting fish in a barrel, Ken. I'm easily confused.  Thanks for the clarification.


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## G MORSCH (Mar 31, 2015)

Gentlemen:  There is a very easy way to predict HP when machining Aluminum or any other material for that matter.  For example 6061T6, pretty common stuff and usually printed on the material.  The Metal Removal Rate (MRR) predicts HP.  This term refers to Cubic Inches of metal removed Per Minute, per HP.  How do we calculate MRR?  Just like we do any other cubic measurement.  Length x Width x Height.   1 Inch Width of Cut x .100 Depth of Cut x 10 Inches per Minute feed will net 1 cubic inch per minute of metal removal.  General standards indicate that 1 HP will remove 4 cubic inches of aluminum per minute.  Steel, including plain carbon, stainless 300 or 400 series, alloy steels and tool steels will require between .85 and .95 HP per cubic inch.  We use these calculations almost every day when we are specifying tooling for our customers.  We also use this method to see if there is room for process improvement when optimizing cutting tool applications.  No matter how you slice it and dice it, one HP will only remove only so much material per minute weather you are milling, drilling, or turning.  A Bridgeport cannot spin a tool too fast for aluminum, even if the tool were 8" in diameter.  Even if we could reach the melting temp. of aluminum, it just can't hurt the carbide all that much in our little machines.  Common production speeds are 2,000 to 6,000 SFM and  10,000 SFM with Poly-Crystalline Diamond (PCD).  (Except when Silicon content exceeds 8%)

Franko:  The tool on E-bay you are looking at is using AMPT1604PDER inserts.  They may do OK in several materials, but, the "P" in the third position indicates that the tool is probably not GROUND and is more than likely molded to size at +/-.0015.  And the "E" near the end indicates that the insert is honed.  (If that position was an "F" in place of the "E" it would indicate a sharp edge with no hone)  
As suggested earlier, look for triangular inserts.  They are common with a radius for turning but also with a facet for fine finishes when milling.  And almost every insert maker makes 3/8 IC triangles.  Look for TPG321, TPG322, ("G" indicates that the insert is ground and will probably be sharp, particularly if it is designated for non-ferrous materials.  Or search for any of the 3/8 IC TPKN style inserts typically used for milling.  Pay attention to the coating....  Best choices for Aluminum are TiCN and even better is TiB2 Titanium Di-Boride.  Aluminum does not adhere easily to TiB2.  Both coatings are bright silver.  I almost always use Tap-Magic of Aluminum.  Use your old toothbrush and brush on a drop or two and you will be delighted with the results.  Pick up some Mag Wheel Polish at the local Auto parts store and you will put a great shine on all your aluminum projects.

Good Luck!
Gary


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## Franko (Mar 31, 2015)

Thanks Gary. Very informative.

I did not order the face mill on eBay, but ordered the one pictured in an above post that is supplied with TPC32 inserts. The inserts I ordered are TPC-321. I think the third number designates the radius of the points. The other inserts I use on my lathe tools have what I think is called a chip breaker (a flute behind the cutting edge).

I ordered a fairly complete (up to .75) set of TiN coated end mills when I bought the mill. They are all still as sharp as I remember when they were new. I think I chipped one when I dropped it. They are all 4-flute end mills. They've always gummed a little at the cutting edge, but I have always run them way too slow. Drill bits have also clogged. Cutting that last part, at higher speed, I had no gumming on the bit.

I keep a small 2-0z. squeeze bottle with a nipple spigot of cutting fluid by the lathe and mill. It says cutting fluid on the label. It looks and feels like thin machine oil. I just drip a drop down the flutes of end mills, drills and taps, and put a drop on the tip of my lathe bits. I saw a guy on uTube use a small can and acid brush to apply cutting fluid. I think I prefer the drip bottle since I don't have to have an open can of something that can spill.

I watched a long uTube video of a guy making a pair of mill stops. It looked like he really knew what he was doing. He had a big spritzer that he sprayed on the parts while cutting. I have no idea what it was, but I'd guess it is like Slugger Cutting Fluid I mix in water to use on my horizontal band saw.


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## Ken_Shea (Mar 31, 2015)

G Morsh,
While I genuinely respect what you seem so knowledgeable on, personally, there's nothing that requires me to learn all that nor do I have any interest or present need. Bottom line I guess is, I chose to remain ignorant in that incredibly confusing area (it's all real easy once you know) and simply purchased HSMAdvisor and it happily calculates all that for you and warns when a cut is beyond a power curve for a particular machine, if I've still a question I call my tool suppliers 

Ken


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## JimDawson (Mar 31, 2015)

Thank you for sharing that Gary.


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## Franko (Apr 1, 2015)

G MORSCH said:


> As suggested earlier, look for triangular inserts.  They are common with a radius for turning but also with a facet for fine finishes when milling.  And almost every insert maker makes 3/8 IC triangles.  Look for TPG321, TPG322, ("G" indicates that the insert is ground and will probably be sharp, particularly if it is designated for non-ferrous materials.  Or search for any of the 3/8 IC TPKN style inserts typically used for milling.  Pay attention to the coating....  Best choices for Aluminum are TiCN and even better is TiB2 Titanium Di-Boride.  Aluminum does not adhere easily to TiB2.  Both coatings are bright silver.  I almost always use Tap-Magic of Aluminum.  Use your old toothbrush and brush on a drop or two and you will be delighted with the results.  Pick up some Mag Wheel Polish at the local Auto parts store and you will put a great shine on all your aluminum projects.



Gary, I have several tools with brazed carbide. It seems like some of them don't perform very well or feel very sharp. If I wanted to touch them up, what grit diamond wheel should I use? I don't have a tool grinder. I do have a fixture that will hold the bits and allow me to rotate them to angles with a veneer scale. I also have a couple cupped wheels, and I plan to make an arbor to adapt them to one of my bench grinders, which should also work with the diamond wheel (or wheels).


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## Franko (Apr 4, 2015)

I finally got around to using my new facing mill.

I'm making some parts out of Delrin. The flats of the 3/4" material had some planer chatter marks and the sawed edges had very minor circular blade marks. Of course, I want them to be perfect to impress my client.

I gang-clamped them in the mill vise to shave the four sides to exact matching dimensions, trimming them flush with the facing mill, removing the saw marks. Then I set them flat and milled off the chatter marks.

I am impressed! It is the prettiest surface I've ever made on my mill. This may be my new favorite tool bit.


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