Type B vs. Type KM ER nut

[zoltan]

Would someone please tell me the difference between a type B and a type KM ER nut? From what I can tell there really isn't any difference.

Type B:
http://www.amazon.com/dp/B00DVTKI7C/?tag=skimlinks_replacement-20

Type KM:
http://www.amazon.com/dp/B00R11N8W8/?tag=skimlinks_replacement-20

 

[Blogwitch]

Hi Zoltan,

It might be cheaper if you purchase from here, even though it is on the other side of the pond.

http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Nuts-Wrenches-and-Spanners

It looks like the two you are looking at are just different manufacturers, as usual, you get the basic, then you get the blinged up ones at double the cost.

The Arc Euro ones are very good indeed


John

 

[10K Pete]

But are they interchangeable for function??

Pete

 

[deverett]

Whichever type/manufacturer you go for, it would be well worth getting the ball bearing nut version.
ER Collet Nuts with Ball Bearing - Type B in Bogs' link above shows them. Also available from other locations.

Dave
The Emerald Isle

 

[Blogwitch]

As with most things Pete, ER collet holders are made with different threads, even in the same size. I think it is to do with the overall OD, smaller ones can get in smaller spaces.

I use ER16, but there are two sizes of threads and so nuts, I use the smaller diameter one, so you must make sure you order the right one for the holder thread even though they hold the same sized collet.


John

 

[10K Pete]

Thanks for the info John. I've been looking at acquiring an ER chuck for
my little mill that uses MT2 collets. I have seen all sorts of nomenclature
for what appears to be the same items. Based upon what you've told me
I should just pay attention to the nut threads as the main compatibility
issue. I've seen some chucks with the smaller nuts and really like the idea
as visibility for the smaller cutters will be improved. So it would seem that
I could probably obtain a smaller nut to fit if the unit doesn't come with a
small one.

Thanks!

Pete

 

[abby]

Pete look for mini nut , these are smaller in diameter than the standard nut , I used one for an ER20 chuck which I made to fit my Pultra
instrument lathe.

.
It works very well and fits both headstock and tailstock , as it is tightened with a spanner it grips better than the original collets especially for tapping under power when I often found the tap would slip .
Oh............remember to order a spanner to fit whatever size you decide on !
Dan.

 

[zoltan]

I'd love to buy from Arc Euro Trade, but unfortunately they won't process my American credit cards.

 

[chucketn]

Their 'terms' page says they take US MasterCard and Visa. I have used a Visa Check Card with them. Bought the ER32 square and hex collet blocks, C spanner, as well as a bearing collet nut from them. Great quality and service.

Chuck

 

[kvom]

Looking at the two photos on Amazon the most apparent difference is the slots for the collet wrench. Plus the KM version is balanced for higher RPMs according to the web page.

 

[zoltan]

Their 'terms' page says they take US MasterCard and Visa. I have used a Visa Check Card with them. Bought the ER32 square and hex collet blocks, C spanner, as well as a bearing collet nut from them. Great quality and service.

Chuck

I know, but when I try to actually pay it rejects me.

 

[chucketn]

I know, but when I try to actually pay it rejects me.

I would e-mail them and find out why, or if there is another method you can use.

Chuck

 

[deverett]

As with most things Pete, ER collet holders are made with different threads, even in the same size. I think it is to do with the overall OD, smaller ones can get in smaller spaces.

I use ER16, but there are two sizes of threads and so nuts, I use the smaller diameter one, so you must make sure you order the right one for the holder thread even though they hold the same sized collet.

John

Well, I've learned something today. I never realised that there were different thread possibilities for the same size ER chucks. When I've ordered spare/replacement nuts for my ER32 chucks, they have always come with the same thread - fortunately. Maybe British suppliers (from whom I have purchased) stick to one standard which may be different from suppliers in other parts of the world.

Thanks for alerting me/all of us, John.

Dave
The Emerald Isle

 

[10K Pete]

I've learned a lot on this subject from you folks and I want to thank you.
Between your comments and looking more closely at the specs in the
catalogs I think I know what to watch for and ask for.

Thank you all!!

Pete

 

[zoltan]

Has anyone ever heard of an ER nut not having the offset flange?

 

[Blogwitch]

You mean where you fit the collet into?

When new, some of these are very tight indeed to get the collet sited, giving the impression that they are not the right size, but after a few ins and outs they do get better as the sharp edges in the nut get round off slightly.

I don't see how a collet can be mounted without that cutout, or offset flange, as you call it.


John

 

[zoltan]

You mean where you fit the collet into?

Yes.

When new, some of these are very tight indeed to get the collet sited, giving the impression that they are not the right size, but after a few ins and outs they do get better as the sharp edges in the nut get round off slightly.

I'm not asking to try and find one without it. I'm asking because I bought a nice ball bearing ER25 nut which didn't have it, and I'm trying to find out if it's just defective, or if I accidentally bought some special style of nut which doesn't have it.

 

[Blogwitch]

Do the collets fit OK into the holder?

Is the runout acceptable when tightened up?

If the answer to both is yes, then just use it.

I am not saying that such beasts don't exist, but are you really sure that there is no relief anywhere around the circumference of the ball race, then something must have been done to allow the collet to fit into position, and if it is just a matter of having a larger hole, allowing the spring of the collet to be compressed to get it through the hole, then I personally see no problem as all the nut does is push on the nose of the collet to close it, so the hole that the collet sits in plays no part in the correct operation of the collet.
The only problem that I would forsee is the collet is not locked into the nut as per normal and so the collet could fall out when it is fully unscrewed from the holder.

Clear as mud he says.

John

 

[zoltan]

Do the collets fit OK into the holder?

Is the runout acceptable when tightened up?

If the answer to both is yes, then just use it.

I am not saying that such beasts don't exist, but are you really sure that there is no relief anywhere around the circumference of the ball race, then something must have been done to allow the collet to fit into position, and if it is just a matter of having a larger hole, allowing the spring of the collet to be compressed to get it through the hole, then I personally see no problem as all the nut does is push on the nose of the collet to close it, so the hole that the collet sits in plays no part in the correct operation of the collet.
The only problem that I would forsee is the collet is not locked into the nut as per normal and so the collet could fall out when it is fully unscrewed from the holder.

Clear as mud he says.

John

The problem is that offset flange provides the self-extraction of the collet. When you loosen the nut it pulls down on the collet and pulls it out of the chuck. Without it you can take the nut off and the collet and tool will remain stuck in the chuck.

 

[chucketn]

What type of collet chuck do you have? is it a flange mount? Taper mount?
If a flange mount it has a through hole. Find a dowell or wood broom handle that will fit through the headstock and the chuck and use that to tap the collet out.

Chuck