End Mills, The Nitty-Gritty: Intro

[Music] [Music] hello everyone and welcome back to Batman unlimited let's talk mils no not not that middle end Mills I've had some viewer requests and actually ahead of your request from a couple of months ago that I'm just now trying to catch up catch up on some of these requests of talking about n Mills now recently a couple other youtubers specifically this old Tony and Adam at a bomb 79 they made some really good videos about lathe tooling high speed lathe tooling lathe insert tooling so we're gonna talk about n mills and I'm gonna split this up into a couple of videos just because there's so much to talk about there's a lot more to an end mill than there is - Lathan sir lathe insert so you have one cutting face end mills you actually have two there's a lot of lot more geometry that goes that goes on with an end mill so before we start I just want to reiterate these videos are for entertainment purposes only and with n Mills there is a lot of fact but there's also a lot of opinion so what I cover in these videos will be what I understand about selecting end mills some of it will be fact that you know I have acquired and that I know is fact some of it will be my opinion and there are a lot of differing opinions on what makes a good end mill and what end mills are good for which purposes and you can see that just by the plethora of manufacturers that will tell you they make the best end mill in the world for cutting material acts there's a lot of them there's a lot of different geometries and everybody is the best so there's a lot of wiggle room here so I just want to set that out ahead time if you're watching these videos and there's something that I didn't cover that you would like to add please comment below and then maybe I'll make an addendum video after we get all of these videos released so that that's how I'm gonna kind of work this so in this episode the first episode we're going to talk about you know what an end mill is we're going to talk about different materials that end mills are made out of and then we'll go from there okay so end mill is simply a cutting tool that is designed to cut mainly on the side so drill bits are designed to cut at the tip so that they can plunge into material and make a hole end mills are designed to run along the side of the material so that we can remove material from the sides okay that's why end mills typically have a flat blunt tip on them so that they can run and cut a wall and the floor and a 90 degree angle at the same time if you want to okay now there are other cuts at the end of end mills you have ball end mills and you have what they call bulldoze end mills where the corners are rounded off and we're gonna get into all those different geometries in the next video and you know when you use them and why you use them etc etc there's a lot to go over here the two biggest material choices that you have are high speed steel and carbide now if you're running a production shop you're probably going to run carbide if you are a home machinist and you just tinker in your garage you may want to stick with high speed steel and then eventually move into carbide okay so I have two end mills here these are two 3/8 inch diameter and mills and they're almost identical this one has a little bit longer like the cut this one has a weld on flat ground into it this one on this side is high speed steel this one is carbide they look strikingly different or they look strikingly similar however what you will find and as you start machining more is if you pick up a tool you will almost instantly be able to tell if it's high speed steel or carbide and the reason for that is the density of the material this end mill weighs about 30 grams this end mill what would you guess it's almost double it weighs 55 grams so this material is almost twice as dense as steel so what does that buy us well carbide is typically harder but more brittle than steel therefore carbide will typically last longer in a cutting application than high speed steel but because it's brittle rather than just dulling it tends to chip and break high speed steel tends to dull and round so that's why a lot of people recommend to Home shops and people that are just starting out machining that they use high speed steel if you make a mistake with carbide it generally just chips you'll hear a little tiny snapping sound and that is normally one of the flutes coming off or if it's a small cutter of a hole cutter coming off or if you hear loud bang followed by some shrapnel sounds that's the hole cutter disintegrating in your machine it's not fun high speed steel tends not to do that it will Bend and give way before it breaks so if you're unsure of feeds and high-speed steals the way to go if this chatters it typically won't break you'll dull it but you'll probably still be able to use it afterwards if you chatter Carbide it almost always chips if you chatter it real bad so carbide while it's stronger and harder it's more brittle so it breaks easier so again you got a choice there now the other big difference is carbide is much more expensive it's harder to make and carb I can't really be cut like steel cans so it has to be ground so it takes longer to grind carbide and Mills than it would have steel it that's why they're more expensive so along with being a little bit less forgiving and more brittle they're also more expensive so when you hear that little tink typically it's anywhere starting from $30 on up to 3 or $400 when you break one of these cutters okay a carbide cutter like this will range anywhere from 150 on up to $500 a steel cutter like this high speed steel you can get it for about a hundred bucks so price difference is significant this carbide end mill is probably on the range of 20 to 30 dollars depending on the quality this one is about 1516 dollars okay so big price difference and you know big sensitivity resistance so these are a lot more sensitive to fees and speeds you got to get it right okay now if you use high speed steel cutting hardened materials maybe some alloy steels they're not going to last very long okay so once you get more comfortable machine and you're going to machine more harder materials switching over to carbide it's gonna save you money in the long run yes these are you know two to three times more expensive sometimes but they last a lot longer because the material is a lot harder now given those differences high-speed steel may still be your first choice depending on what your machining if your machining a plastic or a really soft material high-speed steel because it's not as brittle can be ground to a sharper edge if you grind a really precision sharp edge on carbide it tends to just chip away because the edge is so weak it can't maintain its stability okay so carbide will typically not be as sharp as high-speed steel so in a case of cutting plastic you want really really sharp tooling because the material is soft and it likes to be cut rather than shear if you're machining steel steel tends not to cut it tends to shear away from the cut you want carbide to kind of push through the material rather than actually cut it okay there's a couple of videos I found online that are really cool of enclosed high-speed cameras actually you can actually see the grain separation in the material as you end mill comes in and shears a chunk of it off it's it's pretty cool both to the watch okay so there's a lot of things that decide when you're going between high-speed steel and carbine now along with that there's other materials in the middle okay typically you'll see high-speed steel cobalt which is a little bit harder than your average high speed steel so you get a little bit better tool where goes up another step on the price scale and then after that you'll see some what they call powdered metal tooling okay now powder metal tooling is kind of in between these two it's not as hard as carbide but it's not as soft as steel so it gives you a good mix of rigidity of carbide and tool length of life but it's not as brittle so you can abuse a little bit more so you typically see roughing mills and stuff made out of powdered metals okay so those are your material choices now whatever you do when you're buying tooling remember this is where the rubber meets the road this makes your part don't buy cheap tooling okay there's some outlets that sell and mills Harbor Freight sells and mills unless you're just doing some really simple stuff and playing around and goofing off I would steer clear of that stuff it's not gonna give you good qualities of cut it's not gonna last very long and the money you pay for it if you buy a high quality high speed steel end mill rather than you know a cheaper end mill it will give you much better results it will take less horsepower to run and it will cut like butter okay so spend the money on the tooling don't cheap out it's okay to go high-speed steel you know carbines expensive when you're starting out but don't buy cheap price be nice to buy good stuff okay now let's talk about your machine and your material selections now remember we said carbide you can't sharpen it to as sharp a point in seeking a high speed steel because it's so brittle the edge will just chip on you therefore these aren't a shirt if you've ever used a knife that's dull it takes a lot more force to push it through whatever material cutting so carbide typically you hear me say typically a lot because there's a lot of exceptions carbide will typically use more horsepower to cut than high speed steel or carbide will have a higher surface feet per minute than high speed steel will it's in if you're looking at aluminum it's almost 2 to 1 so high speed steel most consensus maxes out around 600 surface feet per minute you know some push a little harder some a little softer car buy you know I've seen numbers all the way up to two to three thousand surface per minute I tend to run carbide around 1200 surface speed per minute depending on the size of the tool if I get my spindle spinning out okay so again carbide wants higher speed it's gonna take more horsepower than high speed steel okay so that is the carbide high speed steel what type of end mills to purchase video if you have questions or comments please feel free to leave them below if there's anything I missed in this discussion please feel free to add it and we'll hit it up on the next video just as a reminder if you guys want to at man unlimited shirt send me off an email and we can get your shirt out there $25 plus shipping and then also we have our patreon page going so thanks for watching and we'll see you on the next video [Music] [Music]

Channel: At-Man Unlimited Machining

Views: 16,149

Keywords: At-Man Unlimited, At-Man, At Man, AtMan, Machining, CNC Machining, CNC, Machine Shop, Job Shop, DIY, How to, VMC, Fadal, Vertical Machining Center, Milling, End Mill, Geometry, Cutting tool

Id: EB7B1zq8AM8

Length: 13min 42sec (822 seconds)

Published: Fri Jan 27 2017