are used end mills worth anything

[michael a nelson]

i have a chance to get about 100-150 end mills from my shop teacher they are
used are they worth anything? + he has a lot of stuff for metal turning and welding

[Bruce Page]

If you don't have your own milling machine you could probably sell them on CL for a few bucks. I have bought new endmills from CL but I don't waste my time on used.

[Bruce Boone]

The worth won't be in scrapping them; you might get a few bucks. The value would be in resharpening them and getting essentially "new" cutters for a fraction of the cost of new ones.

[Dennis Ford]

I use 1/4", 1/8" and 1/2" shank endmills in routers for woodworking often. A pile of used ones will likely have a few that are usable.

[Terry Beadle]

I agree with Mr. Ford. I use end mills for mortising in my drill press. Works great. I bought the end mills at a garage sale where a machinist passed on and his son was selling all he could.

BTW, end mills can be sharpened if you know how. However, they are really cheap from Grizzly. They last a very long time just milling wood.

[michael a nelson]

does it matter what kind of end mill for drill press use or will they all work?

[Bruce Boone]

It's not good to use an endmill in a drill press. They are normally ground so the outside contacts first, so this won't make a clean drilled hole unless things are really held steady. It takes a vise or clamping to do that. Endmills are designed to cut sideways. The issue with a drill press is that the chuck is usually just held on by a Jacobs taper, and side load will make the chuck come out, so you essentially have a sharp bladed toy top spinning out of control at 2000 rpms that point. Not a fun thing. A milling machine will hold endmills so that they can take a lot of side load by holding the tool with a collet and by using a rigid table with hand feed screws.

There are people out there that specialize in sharpening endmills. It takes special equipment to do it right. I used to send hundreds of carbide enmills to be resharpened at a time and it costs a few bucks each compared to $20 or $30 new. It's true that your outside diameter will be smaller after sharpening, but a CNC can compensate for that, or if just used by hand, it won't matter that much.

[Terry Beadle]

Mr. Boone is right. I will say however that I don't put a side load when using an end mill in my DP. My chuck has never come loose. If you need a really smooth bottom to a mortise then just do a lot of vertical cuts the length of the mortise. I usually over lap the vertical cuts by 10%. Then do a clean up cut on the material between the cut holes. Sharp chisels make short work of cleaning up the sides of the mortise. I stop 1/8th inch from the ends of the mortise and cut those my hand with a mortise chisel.

So you can use end mills on a DP, just don't do surface milling as you would if you were flattening a piece of steel/alum/brass etc.

[Chris Fournier]

Sharpening endmills is quite involved and required some special fixtures to say the least. If you can't reliably sharpen all the flutes in the same manner then you're just wasting time and grinding media.

Using endmills in a drill press is asking for trouble; maybe not today or tomorrow but it will likley bite you at some time. Check out the recent thread that dealt with an endmill pulling out of a collet chuck, now think about an endmill pulling out a jacobs style chuck and arbor - easy to do.

[Paul Saffold]

What about using them in a router? Such as for slots. Thanks.

I just re-read the comments and realized that Dennis answered my question.

[Johnny Kleso]

From my stand point 3/8" and bigger are worth saving if brand name..
It maybe hard to find a good sharpening service these days and depending where you live..
But large shell mills and big cutter are always worth keeping.

You can also hand sharpen them by hand for cutting tool steels
Sharpen the corners at a 45º angle by eye, if the sides are not to bad and just the corners are cooked.
In fact on new cutter I would touch the corners for cutting stuff like D-2 and make them last longer..

On bigger cutter you can sharpen the bottoms by hand..
With a cut off wheel relieve the center with a X cut and then sharpen by hand and eye..
Set the cutter down on a flat surface and look and see if it stands straight up or not..

[Chris Fournier]

From my stand point 3/8" and bigger are worth saving if brand name..
It maybe hard to find a good sharpening service these days and depending where you live..
But large shell mills and big cutter are always worth keeping.

You can also hand sharpen them by hand for cutting tool steels
Sharpen the corners at a 45º angle by eye, if the sides are not to bad and just the corners are cooked.
In fact on new cutter I would touch the corners for cutting stuff like D-2 and make them last longer..

On bigger cutter you can sharpen the bottoms by hand..
With a cut off wheel relieve the center with a X cut and then sharpen by hand and eye..
Set the cutter down on a flat surface and look and see if it stands straight up or not..

I've met several machinists who would advocate handsharpening twist drill bits; they are usually older and use manual machines. I have yet to meet or read of one machinist who would recommend or use a hand sharpened endmill as you have described Johnny. Perhaps you could hone an endmill and not muck up the geometry and symmetry too much but sharpening one? I think that you'd end up with a junk cutter. Any machinist that I know who sharpend his own endmills has taken the trouble to build or buy a tool grinder of some sort.

[Bruce Page]

I've met several machinists who would advocate handsharpening twist drill bits; they are usually older and use manual machines. I have yet to meet or read of one machinist who would recommend or use a hand sharpened endmill as you have described Johnny. Perhaps you could hone an endmill and not muck up the geometry and symmetry too much but sharpening one? I think that you'd end up with a junk cutter. Any machinist that I know who sharpend his own endmills has taken the trouble to build or buy a tool grinder of some sort.

Granted, you need a specialized cutter grinder to sharpen the flutes of an endmill but what Johnny describes is very doable. I have hand ground custom radius’s on the corners of 2-flute endmills more times than I can remember. I have also hand ground flat bottom endmills when I needed to machine a custom diameter counter bore. You need a smooth running bench grinder, a sharp wheel, and a steady hand. It is not that difficult.

[Chris Fournier]

Granted, you need a specialized cutter grinder to sharpen the flutes of an endmill but what Johnny describes is very doable. I have hand ground custom radius’s on the corners of 2-flute endmills more times than I can remember. I have also hand ground flat bottom endmills when I needed to machine a custom diameter counter bore. You need a smooth running bench grinder, a sharp wheel, and a steady hand. It is not that difficult.

I use a surface grinder, magnetic chuck and a fixture to grind the cutting edges on the end of my end mills. If the ends of the flutes aren't at the same height you have only one flute cutting and you then have chatter and poor finishes. I can't see how a bench grinder and a steady hand will get you there as we're into the wee numbers here. I free hand single point cutters on my bench and cup grinders but endmills are another story because the geometry and symmetry need to be spot on. As I mentioned, the machinists that I know who sharpen their own endmills all have tool and cutter grinders of some ilk and as you point out they can do the sides of the flutes as well as the ends.

[Chris Fournier]

Bruce and Johnny, I should also have asked you how you grind your relief angles when you're putting rads on endmills.