# Holding End Mills?



## epanzella (Jul 11, 2019)

Got a new mill drill and I need tooling. I've been scouring the internet on the subject an every time some one has me convinced to us ER32 collets some one else comes along and makes a case for individual R8 end mill holders. As it's a round column machine ER32's would be more convenient  but milling performance trumps convenience. What do you guys use and why?


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## benmychree (Jul 11, 2019)

end mill holders are a good deal smaller in diameter than ER32, sometimes lets you sneak in closer to features on the workpiece that the collet nut may run into.


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## Ed ke6bnl (Jul 11, 2019)

I have R8 with collets & end I'll holders, went with Er32 cheapooes and that is all I got was a set up that does not run true. Seems to be the Er32 collets more than the holder. Got one usa made holder and collets still not running true. FOR ME THAT IS.


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## pontiac428 (Jul 11, 2019)

I use both, but I go out of my way to use R8 end mill holders whenever possible.  Even if it means grinding a reduced shank on a x/32" or x/16" end mill down to the nearest x/8" size.  Reason being is end mill holders are more rigid.  It is probably my own imagination or ignorance, but when considering side loads on collets I visualize a system with some innate room for deflection.  Most say that's a non-issue.  Collets are more convenient and faster to use.  Collets seat better with an aftermarket bearing nut, so you should grab one or two for $15/ea while you're at it.


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## T Bredehoft (Jul 11, 2019)

I use R8 collets and Weldon style holders.  No problem with nuts with them.


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## RJSakowski (Jul 11, 2019)

I use Tormach's TTS system in my Tormach CNC and my mill/drill.  The advantage is my tooling is all set up prior to machining and I can change tooling by changing the TTS ER20 tool holder with tool.  Release of the tool holder usually is accomplish by loosening the drawbar and the holder pops free.  No need to tap the drawbar.  This requires multiple tool holders but my tool offsets are all preset so tool changes are quick and east.  A similar thing can be done with R8 end mill holders but the tool height depends upon the amount of torque applied to the drawbar.

I also have a full set of R8 collets and R8 end mill holders for various diameters.  The R8 end mill holders provide a more rigid tool mounting and they are less prone to pullout during aggressive milling when using end mills with Weldon shanks.  I also use them for larger end mills.


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## Superburban (Jul 11, 2019)

Back to the OP's question. Which is better, an R8 collet/end mill holder, or an R8 adapter with an ER32 holder on the end, and then an ER32 collet? 

Cut the middle man out, and stay with the R8. You can get quality used R8 holders for less then a set of chinesium ER32 collets, and the holder/adapter. 

The little difference in length is not a big deal, If you have the room to slide the end mill out of the holder, it is only a little more to change out the holder. I try to stay with the same diameter shaft tooling, so you just need to loosen the draw bar, give it a slight tap, and swap the tooling.


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## Mitch Alsup (Jul 11, 2019)

Your Mill/Drill will handle both R8 and ER32 (or ER40) R8 collet holder.
a) you may have less runout with straight use of R8 collet as holder (one tolerance error)
b) if you are not looking for great precision, the ER32/40 holder will work just fine.
c) the ER32/40 holder will take up 2-odd inches of space between the bed and nose of the mill

I started with ER40 R8 holder and am migrating towards R8 holders.


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## epanzella (Jul 11, 2019)

Just to be clear here, when speaking of R8's we're talking about R8 end mill holders as opposed to R8 collets, right?


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## mickri (Jul 11, 2019)

I am a newbie.  Here is my take.  I went with ER32 collets for my mill/drill for two main reasons.  First I can use them on my lathe with an ER32/MT2 adapter for the tailstock and headstock and I made an ER32 chuck also.  So one set of tool holders works on both the lathe and mill/drill.  Second is ease of use.  It is a PITA for me to have to loosen the drawbar to change tooling.  I can't easily reach the drawbar.  I have to stand on a stool to loosen the drawbar.  By the time I get the stool, loosen the drawbar, change the tooling and re-tighten everything, and then move the stool out of the way I have spent way more time then what it takes with my ER32 collets.  So ease of use and the ability to use on the lathe and the mill/drill trumped any extra precision I might have gotten from R8 collects.  Cost was a factor too but not the deciding factor.


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## Hawkeye (Jul 11, 2019)

I have all of the above. The most recent addition is the endmill holders, probably about a year ago. They get used the least because I tend to forget I have them. I find that the collet chuck holds more securely than the R8 collets. The collet chuck is the British equivalent of the ER40 style. They hold well and an added advantage on a round-column mill is that the chuck sticks out about the same as a drill chuck. There is less need on a project to change the height of the machine head.


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## Superburban (Jul 12, 2019)

deleted


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## mmcmdl (Jul 12, 2019)

Use both the R8 collets and end mill holders . I've never used ER collets other than on machining centers and have never needed them on any of my Bridgeports .


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## BGHansen (Jul 12, 2019)

I hold end mills directly in R-8 collets, R-8 end mill holders and an ER-32 collet, so not helping you much with your decision . . . .   Advantage of the R-8 collet directly is a little more head space over the table if that's a concern.  I use an ER-32 collet chuck on my Bridgeport to avoid reaching up to loosen the draw bar, nice to change tooling at waist level.  Bottom line is there's no "right way" and you'll find needs/advantages of all methods.

Biggest problem with round column mills is your Z is limited by your quill travel.  One advantage you would see with multiple tooling set ups is maybe gaining some Z by default with the different tooling set ups.  The collet chuck or end mill holder extend more out of the spindle, so you'd start with your tooling a little lower.  Then if you drill a hole and go with an R-8 drill chuck you'd be at about the same point with the drill bit vs. the end mill in Z.  That was always the biggest pain for me with my round column mill; would do some cutting with an end mill mounted in an R-8 collet then switch to a drill chuck and drill and had to crank the head up to get clearance.

My work around back in the day was multiple edge finders fastened to various lengths of drill rod.  Finding center is a basic fundamental technique and shouldn't be feared, it just adds a little time to the job.  If I had to crank the head up/down, I'd refind center by popping in a 1/2" R-8 collet and the appropriate drill rod piece with an edge finder attached and reset the hand wheels.  

Bruce


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## martik777 (Jul 12, 2019)

ER32 is too large and restricts your view. I use ER25 with a R8-ER25 collet chuck on a similar mill - no issues 
Never have needed to use a drill chuck as the collets handle all sizes. 


I do use ER32 on my lathe for the large capacity

Get the full ER25 set, you will eventually need every size, they are under $30









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Make or buy a hex/square collet block to use in your vise etc: 








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## epanzella (Jul 12, 2019)

The general consensus seems to be that I should buy everything! Well naggona happen. I have to pick between a set of ER collets, R8 collets or R8 end mill holders. Time to order. Help[ me out here!


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## T Bredehoft (Jul 12, 2019)

Get the R8 collets,s,  you're gonna need them in any case.


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## tcarrington (Jul 12, 2019)

I would like to have all the above also. IMHO YMMV, etc. 
I have R8 collets on the mill. They work great. Since my mill (PM-25V) isn't very tall, operating the drawbar is not a big deal. Buy a set of R8 collets to use on your mill/drill. It will easily run at feed and speed with a 1/2 end mill. I run larger end mills and achieve great finish and respectable accuracy. With little effort, I can make chips faster that I wish to remove them. You have to learn your machines limitations. They all have them.
If your lathe is a new-ish asian lathe like mine, you might EVENTUALLY go with collets (ERxx), but until then, stick with the 3 and 4 jaw and learn from that process. 
To get more productive on the mill, get a drill chuck on a shank so that you can easily change from drill bit to end mill of a certain size shank (say 1/2 inch), an edge finder of the same size and the tap center / assist. With that, one can easily locate, drill and tap holes in a lot of parts. In certain cases, having a 1/2 inch shank end mill holder to allow quick change to a smaller end mill might be a good thing.
While you could share collets between the lathe and the mill, you might always find (or not find) the collet you want because it is on the other machine. 
For bar stock work on the lathe, I am looking seriously at ER32/40 to reduce runout. I find it unlikely that I would go with ER collets on the mill


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## mikey (Jul 12, 2019)

epanzella said:


> The general consensus seems to be that I should buy everything! Well naggona happen. I have to pick between a set of ER collets, R8 collets or R8 end mill holders. Time to order. Help[ me out here!



The implication here is that you are going to make a one-time choice. That is "naggona happen"!

I know you're anxious to use your machine but the time to think is before you spend your money. I wanted to give you some food for thought:

Any tool system you choose will add to the run out your current spindle has. You need to check your spindle run out and document it so you know where you're starting from. A stock mill drill with stock spindle and stock spindle bearings would do well to have run out under 0.001". Ideally, you want it closer to 0.0001" but that probably won't happen with stock bearings. Just remember that any tool holding system you use will add on to the run out of your spindle.
Really good R8 collets can be really good. Hardinge R8 collets can run out under 0.0002" TIR but these are big bucks. Cheap collets can be really bad; how bad is hard to know. Most Chinese collet makers will claim a low run out number but the reality is often much, much worse. As usual, the best option if you go with R8 collets is to pick a good maker and buy once, cry once. In my opinion, Hardinge is the best, followed by Crawford, Lyndex and I'm sure there are others I have no experience with. I use Crawford. The good thing is that you don't need a full set for end mill holding; you only need sizes to fit the tools you use - 3/16", 1/4", 3/8", 1/2", 5/8" and maybe 3/4" - so you can buy just these sizes from a good maker and do fine. Use a drill chuck for drills instead of using R8 collets to hold drills. Of all your options, R8 collets give you the most headroom in Z because you have almost no stick out of the collet. This sounds good, right? However, most mill drills will have something like 12-14" of Z so headroom is not usually a problem regardless of the tool holding system you use.
End mill holders: I don't use these anymore but they are a good option for larger tooling. I don't care for them because they use a set screw or two to hold the end mill in the holder and this shifts the end mill off to the side, thereby increasing run out. There are end mill holders that are made to reduce this offset but they are more expensive.
ER system: For a hobby guy, I think this is the best option. A decent ER chuck from a good maker is not that expensive, nor are decent ER collet sets. For example, an integral R8-ER 25 or 32 chuck from Glacern is under $90.00. Couple that with a set of Techniks collets that give you the best bang for the buck and you're off and running. ER25 and ER32 sets are available on ebay or Amazon and many other places. It does not pay to use cheap Chinese collet chucks or collets on a milling machine; run out is too high and that affects accuracy, finishes and tool life.
Rather than go through all the pro's and con's of each tool holding system, I'll just add to the other opinions and tell you that after using R8 collets and R8 end mill holders, I prefer the ER system on the mill. I have ER40, ER32 and ER20 chucks for my mill and good collet sets for each. If you have to economize, get a cheaper chuck and spend money on good collets and collet nuts - that is where the real differences are.


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## Buffalo21 (Jul 13, 2019)

I have 3 vertical milling machines, I have R8 collets, end mill holders, ER 32 and EOC 25 (Din 6388) collet chuck systems for all 3.  I rarely use the end mill holders, about 30% of the time is R8 and the rest of the time it’s either the ER 32 or the EOC 25 collets. I do a lot of machining using carbide end mills, for me the collet chuck systems seem to be the most convenient.


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## mksj (Jul 13, 2019)

What works is machine and individual specific. If ER32 is the most convenient then use that, at the end of the day it will not make any difference in the ability to hold an end mill in your mill. You are mostly limited by the design of the mill as to rigidity and TIR. When I had a bench mill w/o a power drawbar I used an ER-32 system because it was the easiest. An ER-32 system will hold tighter tolerances than a R-8 collet system, in particular with the less expensive collets. When I moved to a knee mill with a power drawbar, I have not touched my ER collets and primarily use a CNC chuck and a set of Lindex R-8 collets because the ER system is much less convenient.  I use dedicated R-8 holders for my annular cutters and face mills. If I had a larger mill than the R-8 system becomes the limiting factor. 

You do not need an extensive set of ER collets if using them with most end mills, as the shanks tend to be standard sizes, so something like a 1/8" increment set is fine. If you have an odd ball size you can use the chuck or just get a full imperial sized ER collet set. I will mention that often a metric 1 mm increment ER set is sold because it covers the full clamping range of the collet system, but the clamping range depends on the quality of the collet and the TIR can be pretty terrible at the extremes of the clamping range. I would go with an imperial set, surprised at how inexpensive they are. On the R-8 holder I prefer the nickle plated precision versions, the Shar's one that I use has a TIR ~ 0.0001" and you aren't going to get much better than that. A coated or ball bearing nuts makes tightening easier and can improve accuracy but they are not inexpensive. You need to buy a wrench for the specific nut you will be using.








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						R8 ER32 ER Collet Chuck Tool Holder .0001"
					

<!-- <ul><li>Shank: R8</li><li>Type: ER-32</li><li>Drawbar End: 7/16"-20</li><li>Runout: 0.0001"<br /></li></ul> -->




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## jdedmon91 (Jul 13, 2019)

I say go both ways. The ER 32 has the advantage you can mount up to just up to under 1”. Then if you have adapters for the headstock and tailstock on your lathe. You also have collets for that use. On those round column mills it may be a good option. 

Then you can buy some R8 collets. But you could get by just the common fractional sizes. The your ER 32 will cover the odd gaps. 


Sent from my iPhone using Tapatalk


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## markba633csi (Jul 13, 2019)

I vote for just three R8 collets: 1/4", 3/8", 1/2" , for now.  Drill chuck with 1/2" or R8 shank.   Maybe get into ER stuff later.


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## T Bredehoft (Jul 13, 2019)

markba633csi said:


> or now. Drill chuck with 1/2" or R8 shank



I have a great 0 to 3/8 chuck with a 1 1/4 long half inch shank that I use in my mill. The 3 1/2 shank that came with it was ridiculously long, and the 1/2" R8 collet only has an inch of contact length anyway.


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## stioc (Jul 14, 2019)

For me, R8 collets were ok but once I converted to CNC I went with Tormach TTS adapter and ER20 collets (as RJ did above). Haven't looked back since- the convenience and speed of switching tools doesn't get any better short of having an automatic tool changer.

However, as someone above suggested most of your tooling will likely be 1/4, 3/8 and 1/2 so you can start with a small set of R8s for now and then upgrade to ER later.


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## Toolmaker51 (Jul 14, 2019)

I get paid to mill every day. We have no ER's for R8 spindles at all. I have 4 endmill holders of my own 1/8", 1/4", 3/8", and 1/2". As suggested above, very handy reaching into recesses, being smaller diameter than spindle nose. Everything else is R8 collets. Shop has no small endmill holders, we occasionally use 7/8" and 1" with large roughers facing off square, taking small cuts and the spindle fully retracted. Those are last ditch remedies, most often a long 3/4" rougher suffices.
A drill chuck is not a satisfactory endmill holder what-so-ever. Some drive taps that way. Not good either as a spun tap [higher Rc hardness] galls the jaws, which in turn ruins drill shanks being lower Rc.


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## epanzella (Jul 14, 2019)

For now I've decided to get a set of South Bend R8 collets by 16ths and three R8 end mill holders in 5/8", 3/4" and 1".  I've got a drawer full of endmills with shanks in those three sizes. Experience will tell me if I need ER collets and time will allow me to get good ones if I need them. Thanks to you all for the priceless information!


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## mmcmdl (Jul 14, 2019)

Like I said , been in this trade for 45 years now and never used ER collets in a mill other than cnc machining centers .


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## Investigator (Jul 15, 2019)

Late to this but I'll chime in my $.02

I also have an RF30 mill.  I chose to get the ER32 collet system, along with a metric set of collets.  The metric set I have goes from around 3mm to 20mm and are sized by mm increments.  So I have a collet that fits 7-8mm the next is for 9-10mm.  The cap/closer on the collet chuck can possibly get in the way, but I've not run into that yet.  I felt like this system was good enough for me.  I also use these collets for holding drills and rarely now put the drill chuck in place.  

I am just a hobby guy. I don't make any money on what I do in the shop, in fact the machine work just supports my other hobbies and keeps me going without having to pay someone else.  My goal when getting into this was to hold .005" on what I do, both lathe and mill.  I was able to realize that goal pretty quickly with the tooling I have.  I have only found a few times when I needed more than that, but I have been able to hold .002" on the mill when I needed to, and that was using the ER32 system.

Hope this helps


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## Video_man (Jul 16, 2019)

I have collets and end mill holders for my R8 mill. I always use end mill holders with steel end mllls for the simple reason that collets hold just by friction and end mill holders hold solidly with a set screw on the flat of the end mill.  My carbide end mills, however, are mostly without the flats, so I use collets with them so as not to put point-load from the set screw onto  the brittle carbide.


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## Illinoyance (Jul 16, 2019)

I have R8 collets, end mill holders and ER 16 & 32 collets.  I use whatever is appropriate for the work I am doing.  For heavy cuts I use the endmill holders.  Tools can walk out of collets under heavy loads.

One advantage of the ER collets is the ease of changing tools below the spindle rather than having to reach for the drawbar.


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