Long Length End Mills

Anyone have a source out there for an End Mill and Round Bit that will go 3-4" Deep?

Looking to do a 3D carving that is 6-7" Deep overall. So I’ve split it into sides of 3-3.5" already.


Yeah, not a fan of long end mills but everybody’s got to find out for themselves;


Go for the Harvey Tool. They are crazy expensive and you will break them often so buy extra. Do pay attention to your speeds and feeds calculator’s tool deflection function!

You can also find long Amana tools on Amazon from Tools Today.

You can find long tools from all sorts of Chinese and American manufacturers on Amazon. It takes a bit of searching.

Stubbies are your best friends. Long tools make that tiny runout very pronounced and create vibration and surface finish problems in otherwise tuned systems. They are also very slow.

Now, do not try to use foam specific end mills on anything but. They are evil long, like 5 to 8 inches and they will snap instantly even with mild brushes with your MDF spoilboard. They will always be very clearly marked.

Any suggestions for this project. The Material is 3" thick. From the outside of the pig…it really needs to go the whole 3" deep. From the Inside of the pig is needs to go 2.75" to max out the inner bowl.

The plan is to cut the inner bowl and inside of the legs and ears. Then Flip and do the outside. I’m worried about the spindle hitting the work piece.


A tapered ball nose with a 1/2" shank and appropriate sized tip might be good but I don’t know that anyone makes them.

In regards to the long length and Subnoize’s comment about deflection, you might look for a carbide braze end mill with a Highspeed steel shank. As SN mentioned, carbide is very brittle. A HSS shank will be much more forgiving.

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Or get a shank extender. A bit of google searching for “extra long ball nose” found a few places that sell 1/2" ball nose up to 8" long, and some places have extensions that fit 1/2 and take 1/4 for the finish passes…

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So I’m looking at this:

46590 Extra Long CNC 2D and 3D Carving Flat Bottom 0.10 Deg Straight Angle x 1/4 Dia x 1/2 x 1/4 Shank x 4 Inch Long x 3 Flute Solid Carbide ZrN Coated Reduced Shank Router Bit

My initial run will be on a pine board. I’m thinking a 0.05 pass depth. Better to cut longer and not break my $90 bit I think. With a roughing pass I could probably just sand that down without doing a round bit finish pass.

Eventually, it will be either oak or maple. Maybe a bit of epoxy in there.



Go big or go home? :wink:

These bits say they are for Metals. Do they work ok in wood? I’ve never tried one before?


In general, yes, although wood is more like “aluminum” than steel, so when you have a choice, aluminum bits have a slightly better geometry. Otherwise, the only consideration is the helix angle - they’re pretty aggressive at pulling the wood up on side cuts so lighter cuts and better clamping. A bit of experimentation might be in order for feeds and speeds.

Likewise, you can use standard carbide router bits to cut metal, albeit slowly.

In a one off as a hobbyist, you can get away with it.

Wood is surprisingly abrasive. It will take off your coatings in just a few passes and the end mill will dull as fast as uncoated carbide.

And don’t forget, you get the carbide for free, you pay for the geometry and the coatings.

Certain woods like Douglas Fir (which isn’t really a fir but ok) and Sitka Spruce will dull your end mills very rapidly.

Can you use it? Yes.

Would you use in a production run? Absolutely NOT. You would broke really quickly.

Whiteside is in business for a darn good reason. Uncoated carbide in wood is affordable. My opinion on these Amana Spektra things is still out. We shall see.

Might try something like this.


OK Folks!

I splurged on this the Amana 46590 Extra Long End Mill.

So here are the specs. I’m doing a test piece with either a Pine or Spruce 2x10 from HomeDepot. I planed it flat and glued a few pieces to the correct thickness.

This chart says 215 IPM with an 18k RPM and a chipload of 0.004.

Using the snazzy Avid Chipload Calc spreadsheet for basic numbers - If I slow my RPMs to 12k - where I like to run it. It says my feedrate should be 144…I’m doing a 0.05 layer cut. I want to be conservative…but not burn anything up. Is 40 IPM with a plunge of 10 IPM to low?

I’m not wanting to break my bit the first day.

Thanks for your input,

Personally, I just load the Amana tool from their library, use my calipers to get the correct diameter and go from there. So far they have been spot on. The numbers they give you tend to be conservative.

I would get some scrap and do a test run.

I always start with the manufacturer’s numbers because it makes things easy.

Thoughts on the performance? Is the noise/chatter what you would call acceptable? If not, what should I do to improve it?

Amana 46590 End Mill Bit