End Mills, The Nitty-Gritty: Intro

Hello everyone, welcome to At-Man Unlimited. End Mills, where the metal hits the work piece. They make the chips actually fly. The final link to making good parts.
In this series we will explore the different aspects of end mills. Let’s start with HSS or Carbide and why you would choose one over another.
Please keep in mind throughout this series that this is for entertainment only. While I try my best to have the facts straight I am not a tool designer or supplier. Some items in here are my opinion and should be taken as such. What works for me may not be right for you.

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[wernerberry]

Hi Tim, Thanks for the great videos Buddy!! I personally love carbide and specifically Maritool, Onsrud, and Lakeshore.

[Migman]

i use indexable endmills as im learning.. mistakes are not as bad when a insert breaks from a incorrect feed rate lol but im doing this on a medium sized milling machine so working out feed rates is rather difficult.. have to go by ear most the time. But when it works.. wow the results and speed you can mill something

[Jake-zcfk]

That was excellent, thank you so much!

[melgross]

I generally buy pretty expensive cutting tools. But there are times when I buy cheaper ones. This is traditional, going way back. There is some work where you don’t want to use an expensive tool, such as rough cast iron. Certain steels are best roughed with a cheaper bit, and finished with a good bit.

I’ve also found that Chinese bits these days can be pretty good, and cost very little. For a home shop, they are likely good enough, considering the lower cutting forces and speeds. Additionally, in the home shop it’s not likely that exotic alloys are being used, unless it happens that a cut off that was bought (mystery metal) isn’t what it was thought to be. And even very expensive HSS and carbide tooling can be destroyed if not used properly. Modern carbide bits can be very sharp indeed. We also read that you can’t sharpen/Gringer a carbide insert, but that’s not true either.

There is one guy who, several years ago, had recently started a channel, and is usual with someone with too much money and too little sense, kept breaking 1/8” carbide bits as he was plowing through a piece of steel. He just kept putting new bits in, and a fraction of an inch later, it would snap. He set the table speed by eye “it looks right”, and the revs by guess, and when they started to pop- “I don’t understand what’s wrong”. Yeah, he was “teaching” how to use a mill.

[cncnmore]

Bang followed by anything and I’m sprinting in that direction lol

[vayakbhavin]

sir by powder metal tooling (on 10:03) do you mean powder metallurgy manufactured tools?

[jasonhull]

“Don’t buy cheap tooling”
Unless you are just going to take it home and destroy it promptly in your new import machine….🙋‍♂️

[anthonyhacker]

Good video. But should have mentioned carbide has carbon in it that helps make it more dense and more bridal...hents the name carbide.

[innovativecnc]

Have you had any experience using YG brand endmills, specifically their uncoated alu-power carbide 3 flute for aluminum. I machine aluminum mostly and I haven't had the budget to try many brands. My small machine is only capable of cutting @ 1000mm/min and my spindle rpm ranges from 10k-30k. I usually get semi decent surface finish running a 1/4in Em @ 800-1000mm/min, doc of 4mm, optimal load of 0.8mm and about 17k-18k rpm. Should I be using hss instead since my machine is so slow?

[paulmilligan]

HSS=Absolute useless crap low cobalt content, it will get so dull that it can pull the part out of the vise
HSS Cobalt corncob rougher=excelent for roughing steel stainless and aluminium, cant beat a hss cobalt coated cutter for roughing.

carbide= is my go to for almost everything, using carbide is the best practice for 99 percent of stuff. my favorite is a .500 4flute carbide em with a .900-1.09 length of cut (LOC) I think that different milling machines have preferences for tooling, my fadal 4020 ht loves this tool !!!!

the common denominator is cobalt content there is no such thing as endmill materials specifically for 1018, 4140, 316L, 17-4, 6061 T6, ect. cobalt content is all that matters tooling for soft steels brass ect is low cobalt content and cheep, (cobalt is expensive), stainless and superalloy endmills cut soft materials and hard materials well and have alot of cobalt. and yes coating makes a huge difference on tool life but it can react with cheep coolent and part material. example TILAN

[nitinmundhe]

I like it all video, sir, my request is, pl make video on costing for vmc part with any drawing example.. thanking a lot ..I am India

[rossilake]

Hi Tim, just found your channel. I’m a new an deadly hobby machinist, don’t get me wrong, I’m careful. Still have my 10 fingers and toes.lol. My dumb question is this. I typically use EM’s in my BP, why don’t the used/new carbide EM’s have a flat spot ground into them? Are they designed to in CNC applications only? Back to speeds and feeds? I have some 1” carbide EM’s that I would like to use, slow feed. Any answers would be appreciated. I don’t own R8 1” collet for BP. Remember, I’m a guy in my garage shaping metal and plastics. Thanks you, Ross

[valerierolstad]

Hey... hit me up if you need some end mills. I'm a distributor in SW Missouri and distribute for HTC in MI

[Tapajara]

When you say "carbide" I think you are talking about "tungsten carbide" are you not? As a person with a college minor degree in chemistry I know that "carbide" doesn't exist in nature by itself. Carbon is always bonded to something else if it is one of the carbides. Otherwise its just carbon.

[vincentrolfe]

I have an Austrian boring machine (1500, 3000 rpm) for woodworking. I can slot cut with high speed steel end mills from one northern Illinois brand with razor sharp flat cut end 2 flutes and flutes are razor sharp. YG is telling me that their HSS end mills in 5/8" diameter are not razor sharp due to their finishing process. I had excessive vibration on a shallow cut in walnut and rejected the YG brand. Going to the northern Illinois brand cured the problem. What is the real story about "finishing process" leading to extended tool life?? YG engineering recommended end mills for aluminum but also stated their finishing process would still not be razor sharp.?? thanks

[sunppaa]

Awesome! Can't wait for the next parts!

My personal opinion is, if you have a machine&setup which will not vibrate, and you know a little bit about what youre doing, carbide is the way to go. They last way longer, cut faster and flex less. I have source for reasonably priced alu carbide mills with a really sharp grind, and they just rip thru alu. What's best is they cost only a tiny bit more than some of the best HSS, and perform many times better. Actually I've now run 600 small production parts (plus many other parts) on the same 11eur 4mm carbide end mill and it still cuts like new :-)!

The Harbor Freight type of stuff I don't even like to talk about. Not the end mills nor the machine tools themselves. Except when talking about toys maybe.

[eddyandinc]

sir can you recommend any American company I buy HSS taper end mill ball nose

[pauls]

good stuff but the audio is not sync'd

[graemefenwick]

OK, so I'm late to the party but....
There was a comment about running carbide at 2 to 3 thousand fpm & you run about 1200. So less than some recommend. I imagine you take "spring passes" & finishing cuts, are these lighter still than the 1200?
If I have a smaller machine without the HP to run 3000 fpm. Is there a minimum chip load that must be exceeded? What happens if this is not met?

[gbowne]

Tim, wonderful job on the intro to this series. Very much looking forwards to the rest. Yeah, I know that's a huge rabbit hole. And from years of experience myself, yeah there's some bad information out there, especially for new comers and hobbyists. Yeah, I agree there's a lot of that "Here.. Try this end mill out, it's the best thing...." mostly presented by sales and marketing teams. I know 'cause I test out 'samples' all day long.

There's a lot of variety in Cobalt, usually expressed in a % of Cobalt and/or a M number. Sometimes it says "HSS-Co". (The old way). People doing a lot of "general purpose" cutting should most likely gravitate towards HSS. Yeah, there's loads of value line cheap end mills.

There's a wide variety of end treatment, as in the geometry of the end of the end mill, from curved hooks on the end of the end cutting edges to a more knife edge lookin' hook.

Non-Center cutting and Centercutting.

Then you get into surface treatment, PCD, different coatings, TiN, AlTiN / TiAlN, etc, etc.

Oh, and I recently realized they are starting to make 16 flute end mills. I've heard of some that have a high flute count but that's a lot.