Trying to decide on a general purpose endmill, that will last.

[phantomcow2]

I have collected various endmills, which is what I use for all my projects.
Most are HSS 2 flute uncoated, which don't last all that long. I have a few solid carbides, which are pretty much the ultimate answer.

I dont want to buy separate endmills for aluminum, for steel, all that. I would much prefer just to buy one general purpose endmill of a given size, that I dont need to feel bad about if I mill steel and aluminum. Most of what I do is aluminum, but I do steel about 1/4 of my projects, so I need to be prepared or it.

They must be center cutting, otherwise its a pain. I am fond of larger diameter endmills (largest I go is 1", thats large in benchtop mill world), so carbides of this size get pretty expensive.

My thought was maybe it is best to get HSS endmills, but coated. TiN sem to be very common, you can buy that set of 20 for around 50 bucks. But does the TiN make a big difference? Do some of the other coatings perform better, in terms of wear?

[mrainey]

An overview:

http://www.azom.com/details.asp?ArticleID=943

[NC Cams]

But does the TiN make a big difference? YES

Do some of the other coatings perform better, in terms of wear? YES

Speeds and feeds and coolants and coatings ALL affect the life of cutters.

Ditto that for the various alloys. If you cut 4140PHT, you'll have different life than if you cut 12L14 as opposed to say M2.

Cut 7075T6 and the life will be different than that of 2024.

Carbide is probably your best 'generic' cutter material. Coated is better than non-coated. Asside from that, and unless someone has specific experience to the contrary, you do have to do some tailoring when it comes to cutter selection.

When it comes to finishing, I've yet to see a "fits-all" cutter...

[phantomcow2]

I dont expect a cutter that is optimal for every situation I will encounter.
I just want the best general purpose cutter I can get that lasts a good while, and is reasonably priced. I dont need the type of cutters I use at work, that cost quite a bit, and are used for all the D2 and carbide we mill. I have an X3, not a Mazak.
I do want center cutting though

[DareBee]

Reasonably priced is a relative.
A TiAln coated carbide cutter has an amazing life if run properly in almost any material.
It will be at least double the price of HSS.
Figure out your cost per part when this cutter out lasts the HSS by 4-6X.

I have also been using TiCn coated HSS in larger diameter endmills, I have bee really impressed with these. They are less costly than CBide and have way better life than Tin coated HSS.

[phantomcow2]

I think I will go HSS with TiCn coating.
I know I can't run into steel at 200IPM like the carbide insert cutters do at my work, but my machine is not that cool .
I read somewhere that coolant can be bad for TiAlN. But I don't have compressed air, and need flood coolant to eject chips. Thanks for your advice.

[BobWarfield]

It's pretty hard to just say, "I only want 2 flutes." But, you can economize a bit if you standardize on just a few sizes. I know a lot of fellas who stick almost exclusively to 3/8" and 1/2" diameter end mills, for example. If they need something else they buy it as a one-off.

Beyond that, I would think you want some 2 flutes, some 4 flutes, and some roughing mills. To coat or not is your choice. Coated cuts better and lasts longer, but will cost a little as was mentioned.

Look at some indexable tooling as well. A TPG insert-based face mill is pretty cheap and works pretty well. It may be a little larger investment to buy some indexable tools, but then you just pay for inserts.

Just a few thoughts,

BW

[phantomcow2]

I am going to buy a set of TiN coated HSS endmills. 2 and 4 flute.

But I bought 1", 3/4", a .5" roughers. Also a 3/4" and .5" Solid carbide They are all reground, but I am told cut very well. Plus, the roughers have cobalt in their mix. Even though the diameter is undersize, I prefer it. That way I do the mass material removal with them. Then I bring the workpiece to size with the final passes using my brand new (and presumably correct diameter) endmills. THis saves the wear on them anyways.

[metlcutr55]

my opinion fwiw, the 10 or 20 end mills for $50 sets are junk. i started with a set, they go to hell in a hurry. cheap base metal, and imprpoerly ground. i like niagra endmills, with a TiCn coating. i use more carbide way more than i do hi speed or colbalt, in carbide i like Duramill, they are about 2x the price of the hss niagras, also TiCn coat, 3 flute, they last many times more than a hss cutter. no fancy grinds or TiAlN, standards with TiCn seem to last the best in multi material on my cnc knee mill. good luck.

[phantomcow2]

Thanks for the input.
That being the case, I think I will ask my boss if he can order me some nicer carbide cutters next time they order from MSC. I know he gets them at good prices being a business, so I suppose its worth it to inquire.

[little bubba]

Originally Posted by phantomcow2 I read somewhere that coolant can be bad for TiAlN. But I don't have compressed air, and need flood coolant to eject chips. Thanks for your advice.

I've read that also, and personal experience backs it up. I've found uncoated carbides running with coolant will outlast a TialN coated endmill by about 30%. Recently picked up some TiCN coated, and they are lasting forever running wet.

[big_mak]

Have you considered Cobalt based endmills? They should be tough enough for steel, and still give you reasonable results in aluminum, with out the expense of solid carbide. At my work, we exclusivly use solid carbide endmills from Garr, OSG and RIpper Cutters from Robb Jack (Machines run from 8-15K!!!!). At home however, HSS uncoated are just fine. Just make sure your Surface Speed is good for the cutter material and the work material. This has the biggest effect on your tool life. If you don't get that right, it won't matter if your cutter is made of lead. It will fail.

As for Coolant and TiAlN. Some carbide grades need to be completely flooded with coolant, or use none at all. This is due to something called thermal cracking. This happens when you have an interupted cut. Since the teeth are continuosly in and out of the material, a milling cut is an interupted cut. When you just have a piddly little stream of coolant, the heating and cooling of the cutting edges is more pronounced than if you completely flooded the tool, or had no coolant at all.

So in the end, for a bench top, I'd recommend HSS Cobalt combination, Niagara makes some of these.

I hope this helps.