Hey I use the 1/8” collet quite a bit, we’re down to 1 and I think it’s quite worn, broke two bits on a simple job today I think due to the collet.
I have tried to order a new set but I think our chuck nuts need to be compatible, and whatever I ordered didn’t work. Can someone help me figure out what ones to order? Wouldn’t mind donating a set to the shop I just want them to work.
Thanks
The er number is on the one of the larger collets. I think it is er20 for the router. I generally order nicer ones from Techniks on Amazon. They have less runout and are better built.
Yes, ER20 is what to look for
I bought my own set of ER20 collets in 1/8", 1/4" and 1/2" with one nut, and have found it so much easier to use them without pawing through the ones owned by Asmbly. Mine were from Amazon
I got my own collets but never had any trouble using Asmbly’s nuts.
I’m seeing ER20 A on some of the chuck nuts, I also tried a really cheap collet off Amazon but couldn’t figure out if there’s a difference in fit between ER20A and ER20 - the collet I got when I inserted it wasn’t flush with the chuck nut, it was inset a little and had a couple of cutting errors with depth. Makes me think there’s slight differences, or maybe what I bought was crap.
I might just buy an ER20 A chuck nut with the collet set
Thanks!
I believe the A just denotes that the clamp uses a hex. There is another kind of clamp that is smooth and uses a spanner wrench.
ER20 is the collet size standard. That’s all that is guaranteed to mate up. It doesn’t nail down the spindle thread or outer nut geometry
The intended standard is the suffix denotes the exterior wrench type, but silent on what thread it is internally.
ER20-A is the familiar hex nut, and conventionally M25x1.5 but M24x1 is possible
These all take their own special wrenches:
ER20-UM the round slotted nut and supposed to be M25x1.5 too.
ER20-M is the mini nut and ER20-MS is the mini slotted nut. These are supposed to be M24x1. Note the “M” means “mini”=M24x1 in the case of -M and -MS, but “-UM” is not “mini”, the -UM is always M25x1.5. The M in “-UM” is derived from the German Mutter (nut).
“ER20” with no suffix is just insufficiently labeled, not a different type. I’ve only seen it appear on full size hex, M25x1.5 thread, so those should be labeled “ER20-A”
Most ER20 spindles are M25×1.5 thread, but some use M24x1. That thread has to match. I think the initial REGO-FIX standard was supposed to be ER20 always means M25×1.5 spindle thread, then later the smaller “mini” ER20-M/ER20-MS variants were added which are always a M24x1 spec. But apparently not every vendor got that memo and made ER20-A M24x1 hybrids. Externally, the 20mm hex wrench the ER20-A uses, not a “mini” exterior, but mini M24x1 threads inside. No labeling convention for these. I’m going to be unkind and say “noncompliant abominations”.
You’d think an ER20-A in M24x1 should be labeled “ER20-AM”, but no such labeling standard exists. It SHOULD read “ER20A-M24x1” but not always. “Clamping” is sometimes on the labeling, it has no specific meaning. You’d think something that critical should be clearly designated with a suffix so you don’t pick up the wrong one. Wrenching the M25x1.5 nut on an M24x1 spindle thread could damage the spindle.
What you might want to look into is a bearing nut. The ER collet always presses into the spindle taper first and stops turning vs the spindle, the nut then tightens down by turning across the front 30 deg chamfer of the collet to press it in. That’s a lot of friction when tightening and it doesn’t make it hold better. Bearing collets have an axial thrust bearing where it presses on the collet chamfer, so it’s much less friction to tighten down. The bearing races only have relative motion while tightening, they don’t move against one another when the spindle runs.
For ER20 bearing nuts, I see a hex type “ER20B-A”, hex type “ER20GM”, one with slots on bottom also “ER20GM”- well, that already breaks the system where suffix indicates wrench style), and one with mid-slots (hooked “C” wrench) “CN20-B” which is still ER20 system.
Some ER25 bearing nut searching got me “OZ25”, that’s the OZ collet system which is incompatible with REGO-FIX’s ERxx collet systems.
I did once try an ER20 vacuum “DUST CHIP EXTRACTION NUT” which has its own fan vanes in the nut.
Innovative concept, but terrible. All aluminum IIRC, softer, still added a ton of inertia, needs extra clearance on sides. But it also has vanes that reach down below the normal nut front face, so you lose something like 10mm of usable bit length too. Fan power is basically cube of RPM, so insignificant suction at lower speeds and gets strong flow but draggy on the spindle power by 20KRPM. Any stringy debris could hang in a fan slot and create a significant balance prob. For wood CNC, it can’t replace a dust collector, and if you have a dust collector, this seems redundant.
Fun to play with, but it wasn’t a good idea overall in any setup I am familiar with
