ER25 vs ER32 ?

[DanH]

Is the difference between the ER25 and ER32 collets just the added capacity? I am looking at getting a set for my RF45 clone but I don't know which size I should go with. From my reading I tend to think the ER25 size would be fine but my lack of experience with either size makes me hesitant to pull the trigger.

Dan

[DaveH]

Dan,

One thing to know is the ER25 and the ER32 collets are not interchangeable.
That is to say an ER25 collet will not fit into an ER32 collet holder.
ER25 the range is 1mm to 16mm
ER32 the range is 2mm to 20mm
If you plan on using larger end mills than 16mm go for the ER32
That's my 2c's

DaveH

[Bill Gruby]

As Dave said, they are not interchangeable. This is because of their ranges. See below for dimensions. ER 25 is on the left, ER 32 right.

"Billy G"

[Mayhem]

Another thing to note about ER collets is that the collet needs to be inserted into the nut before being placed in the holder. This is taken from the Tools4Cheap web site:

http://www.tools4cheap.net/proddetail.php?prod=er32 Wrote:The nut has a offset ring inside of it. You must put the collet into the nut at an angle and then straighten it. You then install both the collet and nut together on to the holder. If you try to put the collet in the holder 1st and then put the nut on, it will not fit and you could damage the parts.

Edit: Link to additional information, including a diagram on using ER collets on the Arc Euro Trade site

[henryarnold]

This is an interesting discussion. I bought an ER40 set for my mill and recently bought an ER40 - MT4 setup for my lathe. Now I am able to use the same collets on both my mill and lathe. I didn't do much research before going with ER40. What are the advantages of going with ER25 or ER32? Is it just that they are smaller in size?

My original set had an R8 mount holder which had fairly poor run-out so I ended up replacing it with a holder from Maritool. Luckily all of the collets were fine.

[Mayhem]

Henry, I can only see that the smaller series allow you to hold smaller diameter items. Also, the clamping range is reduced on the smaller collets. Perhaps the larger series encroach more into the work envelope but I am unsure if this would be sufficient to warrant going down in capacity.

I too would have gone with ER40 but the mill came with an ER32 chuck and collets. Eventually I will make an ER32 collet chuck for my lathe.

[DanH]

I didn't even think about the ER40 size. So it seems there isn't a clear cut reason to pick one size over another. I'll look at the size range for the 40 as well.

Dan

[Bill Gruby]

Morse Taper 3 ER40 in my 9X20. I use it extensively.

"Billy G"

[doubleboost]

Hi
I use ER32 very happy with them
I use them on the lathe, mill and have made various fixtures for them
John

[henryarnold]

Guys,

Thanks. Here's the MT4 - ER40 Chuck I bought. I used a 11" x 5/8" black oxide bolt with a a custom shoulder washer I made as my draw bar it works great. I mounted a 3/4" piece of drill rod in a 3/4" collet and found the run-out on my setup was +/-0.00025. I think that is very good for a $50 chuck.


  chuck5.jpg (Size: 3.64 KB / Downloads: 83)

If you need an ER chuck for mill or lathe, the EBay seller I purchased from sells ER25, ER32, ER40 chucks and collets.

http://www.ebay.com/itm/330497192569?ssP...1497.l2649