Help me choose an end mill for routing wood

[John Rauch]

All,

I've done a bit of reading/searching on SMC and other forums about using an end mill in place of a router bit -- mostly to save a few bucks.

My application is making several mortises (1.5 inches deep by 1/2 inch wide) and I've found a number of end mills whose diameter and cutting length should be appropriate. The end mills I've found are available from Enco, MSC, etc.

I plan to order from Enco, and their site allows you to choose from among a host of specs/features such as "aluminum cutting", "roughers", "standard", etc.

If you happen to choose an aluminum cutting end mill (suggested in some of the reading I've done) on the Enco site, you can then choose a type such as "center cutting," "regular", "roughing end mill", etc. There are further choices to be made after that as well.

I know nothing about machining metal and need guidance on purchasing a mill appropriate for my application.

Anyone care to make specific suggestions and/or report the experience they've had using an end mill in place of a regular router bit?

Thanks in advance for your input.

[Brian Hale]

Roughing... NO

High helix... No

Coated.... No

Just a standard 2 flute center cutting endmill. Here at work we use Garr solid carbide endmills as a general purpose utility endmill and when they get dull or chipped i take them home with me for a second life.

I've been a machinist for quite awhile now if you have any more questions.

[Rick Lizek]

HSS center cut is what we use on our slot mortiser at around 5,000 rpm. They will last for years cutting wood and they're very inexpensive to sharpen. Enco bits are fine.

[William Adams]

All of those terms should be defined here: http://www.shapeoko.com/wiki/index.php/Endmills

[Peter Quinn]

I used to run HSS and occasionally carbide 3 flute or 4 flute roughing end mills made for aluminum on a Bridgeport for mortising hardwoods for very deep mortises. Always center cutting or you have to sweep into each pass because they wont plunge. The surface quality is fine for mortise walls and the feed rate was a bit quicker. Do check the max RPM's on the end mills you purchase if spinning them on a router, not all tooling is made to go 18K rpm!

[Bruce Page]

The geometry of a metal cutting endmill is different from that of a router bit. My experience has been that I can cut wood all day using endmills in my milling machine @ 2000 rpm but when I use them @ 10k+ rpm in my router table or CNC router they will overheat and dull quicker.

YMMV

[Bryan Rocker]

Thanks for the linky, very informative....

[John Rauch]

I will double check, but I don't recall seeing a max rpm for the end mills I reviewed on the Enco site. Going to test the end mill using a variable speed Hitachi MV12 router - don't recall its slowest rpm. I'll report back on how things go in the next few weeks. Thanks for the input.

[John Rauch]

Yes, helpful link.

[Bruce Wrenn]

Harbor Freight sells a set of three HSS mortising bits, 1/4", 3'8", and 1/2" for around $13, minus 20% of coupon. Sometimes (often) they are on sale for $9.99. Highly recommend them, own two sets.

[John Rauch]

I received my copy of Woodsmith magazine in yesterday's mail and coincidentally there is an article about using end mills. The article suggested using a 'roughing' style, 4 flute end mill for mortises.

[Pat Barry]

What is the price difference between an end mill bit and a carbide router bit with 1/2 shank. For example the Blue ones you can get at Rockler? Wouldn't the carbide be a lot better at holding an edge and last a lot longer than the end mill? What does it cost to get an end mill resharpened?

[Jim Andrew]

I called MLCS to ask what router bits to use for mortising, and they told me to buy
spiral upcut router bits. Of course all I find are solid carbide.

[John Rauch]

A 1/2 end mill, center cutting, two flute, HSS at Enco with a cutting length of 1.5 inches is about $14. Just as a point of comparison to MLCS, their router bit is $40 for an equivalent cutting size. See bit #7468 on the MLCS site. The router bit is two flute, up-cut, solid carbide.

I am not endorsing Enco or MLCS, but wanted to have a general price comparison.