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View Full Version : General Metalworking are used end mills worth anything



michael a nelson
05-02-2011, 5:21 PM
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
05-02-2011, 5:32 PM
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
05-02-2011, 10:26 PM
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
05-03-2011, 8:57 AM
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
05-04-2011, 5:22 PM
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
05-04-2011, 6:05 PM
does it matter what kind of end mill for drill press use or will they all work?

Bruce Boone
05-04-2011, 8:13 PM
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
06-02-2011, 12:43 PM
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
06-04-2011, 12:08 PM
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
06-04-2011, 10:13 PM
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
06-07-2011, 1:27 AM
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
06-07-2011, 9:46 AM
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
06-07-2011, 4:21 PM
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
06-07-2011, 4:59 PM
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
06-07-2011, 6:04 PM
Bruce and Johnny, I should also have asked you how you grind your relief angles when you're putting rads on endmills.

Bruce Page
06-07-2011, 6:05 PM
Well Chris, I guess I am old school. When I served my apprenticeship we were taught cutter geometry and how to sharpen spade drills, twist drills, and how to touch up endmills by hand. We weren’t given the time to set up as you describe.
Because you “can't see how a bench grinder and a steady hand will get you there” doesn’t mean that it can’t be done.
“Old school” machinists like myself learned to make complex “CNC” like parts before CNC even existed. We were proudly called “Conventional Machinists” and could deftly run any machine in the shop from OD/ID grinders to gear hobbers. Many of today’s production machinist would fall flat on their face if they were handed a complex part drawing and told to make it on a conventional Bridgeport and engine lathe.

Leigh Betsch
06-08-2011, 12:46 AM
To a machinist these might have some value but in my experience I don't buy used cutting tools, period. I've been burned. I buy new then resharpen when they get dull. I sharpen by hand and eyeball since I'm now a home shop machinist and don't cut metal for a living anymore. When I did this for a living I sent cutters to a pro to sharpen them becasue they needed to be right and the guys in the shop could make more money making molds and dies than they could save by sharpening cutters themselves.
So my advise is if you can use them yourself and you can sharpen them yourself then you don't really need my advise, if this isn't the case then I would pass becasue you probably can't sell them to anyone for much money anyway.

Chris Fournier
06-08-2011, 11:07 AM
Well Chris, I guess I am old school. When I served my apprenticeship we were taught cutter geometry and how to sharpen spade drills, twist drills, and how to touch up endmills by hand. We weren’t given the time to set up as you describe.
Because you “can't see how a bench grinder and a steady hand will get you there” doesn’t mean that it can’t be done.
“Old school” machinists like myself learned to make complex “CNC” like parts before CNC even existed. We were proudly called “Conventional Machinists” and could deftly run any machine in the shop from OD/ID grinders to gear hobbers. Many of today’s production machinist would fall flat on their face if they were handed a complex part drawing and told to make it on a conventional Bridgeport and engine lathe.


The guys that have taught me are old school as well Bruce and there doesn't seem to be a machine, process, or operation they haven't done! I strongly agree that there is a difference between the current "machine feeders" and fellows like yourself. I have to say that having used a CNC mill over the last year, there are subtlties to getting a good vs great product but I would take an old timer over a CNC expert if I could only engage the services of one or the other. I would provide the Conventional machinist with sharp cutters from my own tool crib and let him make chips!

Johnny Kleso
06-08-2011, 11:46 PM
Chris the guys that taught me did not use milling machines to drill holes..
They where all done on a lathe with face plates.. Thats how old school they where..

When I sharpened the bottoms most I was doing the most high tech work I ever did.. Making the GPS's in the 80's and B-2 Bomber parts..
Mostly carbide EMs I sharpened bottoms and the owner was to cheap to buy a surface grinder fixtuer like you use, but after I left and came back a few years later he finally broke down and bought one..

For roughing tool steel so what if the bottom of flutes dont meet flush and are off .005 out of four flutes taking a .025 cut..
For a CNC's them guys want only the best of the best and still break and crash stuff.

I bought about 25 lbs of small carbide EM's off eBay and all where like new almost but all where from one seller..
He did super precision CNC work and changed tools by time clock not by when they he though they were dulled..
I would not buy used HSS EM's unless I knew where to get them sharpened cheap and knew they were name brand / USA

george wilson
07-22-2011, 1:42 PM
I sharpen drills by hand. Used to could do a 1/64" drill by hand,using a bench stone moved vertically up and down with 1 hand,while the drill was presented with the other hand. One day I was drilling a bunch of holes,and had to resharpen the bit several times that day as I had no other on hand. I use 4X drug store eye glasses when doing things like that.

For end mills, I have a K.O.Lee tool and cutter grinder,and an old Weldon end mill sharpening fixture. Not air bearing,but still works just fine.

Glen Butler
09-18-2011, 6:41 AM
You can get TiN coated endmills for a few dollars through ebay. I have bought several and I am impressed with there cut quality and life. I feel an endmill under 1/2 is not worth sharpening, but if they are larger, go for it.

george wilson
09-24-2011, 7:23 PM
When I was much younger,and poorer,I had no way other than to sharpen end mills by hand. They were serviceable for home shop use,but of course not as perfect as those sharpened in a proper fixture. I got my little K.O. Lee Knockout in the 70's,and still have it.