Need help understanding differences between collets: ER32 vs. ER24, ect.

[GunsOfNavarone]

So about half are unequal hole size, have look to be the same at both ends.

 

[Larry$]

Interesting discussion. As usual mostly it boils down to what you are going to make. In our woodworking shop we have ER32 collets for holding tools. In my hobby area I've got 5C. It takes a lot of 5C collets to cover the entire range up to 1 1/8". I've got several for squares and a couple for hex. I got a very nice runtru 5C collet chuck from Quality Tool (PM) that I use a lot. Same collets get used in the spin indexer, collet blocks and tool grinder. Any time I have a series of parts to make, I install the interior depth stop on the 5C collet. I made a spider for the lathe so I can support long work thru the collet chuck. For the widest clamping range look @ rubber collets. A nice thing about collets is you can clamp directly on threads, or even end mills.

 

[Tozguy]

So about half are unequal hole size, have look to be the same at both ends.

My ER32 collets are the same. The smaller sizes of collets are recessed (counter bored) but the larger ones are not.
My guess is that contact in the collet bore does not have to be the full length for the smaller diameters. So the collet is counterbored to make it more springy and easier to collapse onto the work.

 

[TacticalAnt]

Well guys, i settled on Techniks ER40 collets and a HHIP hex collet block. I got a really good price (i think) on collets from All Industrial. They are working with Techniks for a buy 2 get 1 free promo. And their normal price is $17.50 ea. Also free shipping . In the mean time, I made a collet to hold my Micarta rod. Cut the slits with my bandsaw. Holds it quite well.
The bore looks nasty, I have not received my boring bar set so I had to make a boring bar from an old HSS 1/2” drill bit.

 

[.LMS.]

@TacticalAnt - how did you get the buy 2 get one free promo? I don't see it on their site.

 

[TacticalAnt]

@TacticalAnt - how did you get the buy 2 get one free promo? I don't see it on their site.

Right, you have to call and ask. I spoke with Scott Schultz and he took care of me.