Well, let me see if I have this straight (using that site!!!)~ you have 18g wire, that's 0.040" according to the chart I just googled... So 0.040 * 4 = 0.160" which would be the minimum ID needed for a 4 in 1... Right???

Ummm...not exactly. And I am going to apologize ahead of time. I perceive myself to have a tendency to be kind of lecturing sometimes. Stop now if you think you might have a problem with lecturing

I think where your logic went is "I need to put 4 wire diameters in through a ring so my ID needs to be 4 times the wire diameter," correct? That is true if you were wanting to try to line up 4 wire diameters straight across the midpoint of the ring. Not so true when you have the 4 wire diameters oriented in a roughly square pattern within the ID of the ring.

Quick AR primer time

AR, or Aspect Ratio, is a unitless number used to describe the relation between the inside diameter and the wire diameter of the ring. Please note that we of the maille sort use inside diameter while more jewelry oriented sorts may use outside diameter. AR is calculated by taking the inside diameter of the the ring and dividing it by the wire diameter. Written in an equation, AR=ID/WD. Now, with some basic math, given any two pieces of that equation we can adjust it to find the third.

So, for the E4 example using David's chart.

If we are shooting for the

**minimum** AR, that is 2.9. We have the wire diameter for 18awg wire, which is .04". So, 2.9=ID/.04" which is the same as 2.9*.04"=ID or .116". The nearest Imperial measurement to that is 15/128" at .117". So, you'd end up with slightly higher than minimum AR, but that would work.

Now, David's chart also says that anywhere between 3.0 and 5.5 AR is pretty good for E4, but 3.3 is his preferred sweet spot. So, we have some more numbers we could plug into that equation. Let's see about 5.5 AR.

5.5=ID/.04" or 5.5*.04=ID

5.5*.04"=.22"

It looks like 7/32" (.219") or 29/128" (.227") are your closest Imperial measurements depending on whether you want to go a little over or a little under 5.5AR.

Maille Etc's 18AWG is approximately 1.024mm and is going on a 5mm mandrel.

AR=5/1.024=4.883AR

Well withing David's preferred AR range for E4.

So, did that help or hinder?

Now, regarding the original poster's queries, the large the ID, the floppier E4 is going to be unless it's pulled tight. If it's a fairly secure choker, it may be alright. However, this is all theoretical, as I haven't done a 3 row 18AWG E4 choker

If you are using SS in the jewelry sense, I'm going to guess that's sterling silver and not stainless steel, which is how I tend to interpret it

. Keep in mind that the larger the ID, the weaker the chain will be, and a softer temper metal may not hold up to the necessary stresses. Also, if she even has a ruler handy and can give you a rough idea of the ID, you'd have a bit better starting point. Sorry if I'm just giving you more questions rather than answers.

Meh, I just noticed I'm a few days late. Well, some of this may still be useful