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View Full Version : End Mill Quality Experiment - Help Wanted



rustydog
12-12-2012, 11:15 PM
I'm a self taught beginner machinist. I started on a Mill Drill and have moved up to a Grizzly 0731 which is a small knee style mill. I have been using Enco end mills from their bargan boxed sets. They have worked from poor to reasonably well over a range of projects. I know I can get a better finish with better quality end mills. I'd like to put together an experiment where I use a range of cutters from the low cost, like I have been using, to a medium price level cutter. I'll run the cutters through a variety of steels from mild to O1 to get a better understanding of how end mill cost / quality affects my finish. I would be pleased to have any suggestions as to the particular brand and style of cutter I should consider. I'm on a budget which is why I mentioned medium price level cutters as the upper end for the time being..

darryl
12-12-2012, 11:40 PM
Yes, I'd like to see the results of such an experiment as well. The one thing that bothers me is how do you know that the endmill you have bought is a good quality one- it may have a brand name on it, but is it the 'real thing'? I'd like to trust a brand name, but I don't know that you can anymore.

What I do is ask questions at metal shops where they use tooling a lot. Chances are they are going to know what's good and what isn't, and also what is a good bang for the buck. If you don't want to pay top dollar for a cutter (and I'm sure the shops don't want to either) then maybe follow their lead and buy the brand they use. That has worked for me.

One tool in particular, taps- my local shop uses Yamawa taps. I've bought from them at reasonable prices, and they are the best taps I've ever used. Not saying they are the best- I wouldn't know from experience- but they do work well and last well.

What I do is probably best described as hobby machining, and as such I can't afford expensive tooling either. But I also can't afford poor tooling- and there's a lot of it out there.

beanbag
12-13-2012, 12:20 AM
What affects the finish is things like coolant / lubrication use, chip clearing, good toolpaths, condition of endmill, and the proper feeds and speeds.

As long as the endmill is not made in china, you should be ok.

Jaakko Fagerlund
12-13-2012, 04:01 AM
As long as the endmill is not made in china, you should be ok.
You get crap if you pay pennies, no matter where it is from. Have had good examples in the past with some Americrap products that were cheap and it showed.

Grind Hard
12-13-2012, 06:27 AM
I did this years back with turret-punch tooling. It was quite eye-opening to see that some of the "premium brands" were mush compared to the "lowball brands."

I suspect endmills, inserts, grinding wheels and other consumable toolings are the same way. Often times the premium brand is a whitewash by the sales team with slick advertising, fast-talking field agents preying on clueless managers and other assorted tactics.

BigJohnT
12-13-2012, 07:31 AM
Being on a budget makes it hard to think about purchasing cost effective tooling like carbide end mills. There are so many factors that come into play that it is impossible to say what will work for you. I use solid carbide tooling from Lakeshore Carbide for anything < 3/4". Take for example a 1/4" 2 flute std length end mill (http://www.lakeshorecarbide.com/14variable2fluteendmillforaluminumzrn.aspx) with corner radius and it is $26 but it will last a long long long long time cutting aluminum or plastic. While $26 sounds like a lot of money for an end mill in perspective it is less than a half a tank of gas. Back to HHS tooling the difference between a dead sharp corner and one with a 2 or 3 thou radius in cutting life can be dramatic. The devil is in the details when it comes to metal removal. How rigid your machine and spindle is will make a huge difference on tooling life. Even material purity can make a difference... I assume that is why all feed and speed information from tooling manufacturers is a recommendation and not set in stone.

John

Weston Bye
12-13-2012, 08:03 AM
Just some anecdotal evidence: I purchased some solid carbide engraving cutters and endmills from 2Linc.com - they are advertising on this BBS - their ad came up for me at the top of this page.

I am pleased with the initial results. Cutting 1/8" 6061 aluminum with a 1/8" endmill, dry, on my homemade CNC, the endmill is able to cut .070" deep at 5 ipm and 10K rpm. Might not be fast by someone else's standards, but faster than with other endmills of unknown pedigree. I have cut out all 12 of the wheels for my Magnetic Clock, plunging for the magnet pockets and profiling out the shapes of the wheels, with one of the 2L endmills and it shows no signs of wear or reduced performance.

I haven't tried to find out what the upper performance limit is - no point in breaking a good endmill.

Black_Moons
12-13-2012, 08:13 AM
Buy a good cobalt HSS rougher endmill (With the funky wavy flutes), Saves all your good endmills for when they are really needed.

browne92
12-13-2012, 10:29 AM
What I do is ask questions at metal shops where they use tooling a lot.

To add to this, I would say talk to an independent shop, where the owner is paying for tooling out of his own pocket, not some large industry shop where nobody in the place knows what anything costs because the purchasing agent gets it all out of the Grainger catalog.

Mike Hunter
12-13-2012, 11:07 AM
Don’t think you even need to waste your time or money on buying cheap (read crappy) end mills.

I went that route once years ago, big mistake. I ordered a bunch of import end mills from Shars; hey $5 each for inch HSS end mills… what a deal, I cant even buy blank HSS rounds for that price.

What a mistake… they wouldn’t cut worth a darn, dulled easily, just plain old garbage… even had one melt/burn up on me… inch EM moderate cut on 1018, had the power feed on… watched the tip of the EM get red hot and melt in about 3 seconds…. I just stood there in amazement with my jaw on the floor.

Don’t know if there is an actual term but I call it Form Function, it looks like an end mill, feels like an end mill but its not an end mill… kinda like wax fruit, some look good enough to eat.

Finally decided to try a quality End Mill, what a difference, cut thru 4140 like butter, no problems… it was sweet.

Take a look at Enco’s Hot Deals flyer they always have Atrax or Melin end mills in there, wait for a 15% or 20% off deal and take advantage if it.
Case in point, in Enco’s hot deal flyer you can get Atrax inch Carbide end mills for 18.99, 15% off and your cost is down around $16. That’s dirt cheap for a quality product.

Mcgyver
12-13-2012, 11:32 AM
I'm a self taught beginner machinist. I started on a Mill Drill and have moved up to a Grizzly 0731 which is a small knee style mill. I have been using Enco end mills from their bargan boxed sets. They have worked from poor to reasonably well over a range of projects. I know I can get a better finish with better quality end mills. I'd like to put together an experiment where I use a range of cutters from the low cost, like I have been using, to a medium price level cutter. I'll run the cutters through a variety of steels from mild to O1 to get a better understanding of how end mill cost / quality affects my finish. I would be pleased to have any suggestions as to the particular brand and style of cutter I should consider. I'm on a budget which is why I mentioned medium price level cutters as the upper end for the time being..

its a big, complicated experiment given the number of variables....one of which is the end mills you use. One cheapo vs one expensive brand is of itself insufficient; you'd to have several different cheapos and quality ones to say the results are representative of each catagory.

The margins in many industrial products are so extreme there is the possibility of behind the scenes trading to the extent where might not really know who makes what. I've seem item you or I have to pay $30 trade oem for $8. Spreads like that mean you just don't know who's buying from who behind the scenes.

michigan doug
12-13-2012, 02:09 PM
I watch ebay and pick up carbide EM's, different brands, etc. New, not resharpened. Never got a carbide end mill that didn't perform at least pretty good, if not outstanding.

doug

Toolguy
12-13-2012, 02:25 PM
I use carbide a lot, but have found on McMaster-Carr, endmills for aluminum. They are Niagra brand 3 flute with 37 degree helix. The are my go to endmill for cutting anything soft like wood, Delrin or other hard plastic, but especially aluminum. They are premium quality for a fairly low price. They cut alum. a lot better than the generic 30 degree helix ones. They also have these in a roughing config. for when you have to move a lot of material before finishing.

MasterMaker
12-13-2012, 06:15 PM
Actually some cheap endmills can be quite good.

A local china-box store used to have tin coated endmills up to 20mm(if memory serves that size was about 20$(which is cheap here)) that were very good.

Then they stopped selling the 20 mm ones and the max size went down to 16mm, then they changed the brand to endmills made for them under their in house brand that wasn't center cutting and with a tin coating that looked more like cadmium zink.

These were less great.

I've also come across drill bits(also tin coated) that while cheap and no-name china made rivaled Dormer or Guhring in performance, so there is definitively some very cheap cutting tools available that are very good.

Tin coating might be a clue to whether or not something is of a higher quality as I don't think makers of crap will bother with wasting money on an additional manufacturing step.

JEZX
12-13-2012, 06:17 PM
i have tons of endmills from lots of makers , all will make a nice finish if they are sharp . ive used alot of china made (busy bee ) end mills with great success on aluminum , for harder steel i may aswell use my finger nail , even the carbide from busy bee is soft .
ive bought some carbide endmills from freud (for wood router) they are a very solid end mill but only in 1/2'' and 1/4 . but the 1/4'' has 1'' flute
the niagra , skf , doall ,all seem good aswell

Black_Moons
12-13-2012, 07:04 PM
I have a toolbox thats a very good clone of those expensive wooden toolboxes, Except theres finger joints all over it in visable areas. Even has the nice felt lining in the drawers.

Im convinced they made it in the exact same factory as the 'real' toolboxes, Except it was built with all the leftover scraps and wood that didn't meet the required grade. Maybe by someone who was learning the ropes (But still seems to know what they are doing)

Sometimes I wonder if the same does not happen with endmills and such. When labour and materials are 'free' you don't exactly care to spend money on training that does not produce a product.

My biggest beef with chinese tools has to be the sharpening. Brazed carbide tooling (Lathe bits, saws, router bits, hell even HSS wood lathe tools) often looks like it was sharpened by draging it across the sidewalk. some time with a diamond hone however and its very nice and functional.

So maybe the cheapo drill bits/endmills are the result of training employees to run the sharpener for Y amount of time.
If they learn to produce good endmills before X amount of time, well sharpened endmills hit the market for low cost, since non existant quality control isent going to see those endmills are good enough to be sold as <X> brand.

And then those same people get to make endmills for <X> brand after Y amount of time, reguardless if they have learned how to do it or not.. (Hence why we get some really poorly made branded tools from time to time). After all, Checking if they have learned there job would cost more money, Money they are not getting paid to do.

Grind Hard
12-13-2012, 07:42 PM
Many products are manufactured "all under one roof" and they simply grade them from good to not so good and brand-label them according to how much that brand was willing to pay.

Batteries are a great example. The Dollar Store ones are the ones that failed quality control while the Wegmans (Supermarket Chain) ones are a bit better in grade while the "name brand" ones are the best of the lot.

That's why you see the "off brand" ones sold in bulk for the same price as a pack of four "brand" ones.