What is the reason for [insert mm here] size ID? What's your favorite?

I feel like this has been talked about before, but couldn’t find anything. Not being a big coil builder, I never have understood the reason for a specific ID. There was talk in chat about how the Bellus doesn’t really have room for 3mm coils and it made me wonder…why would you want that? It seems to me that a smaller ID (within reason) would be better because a smaller diameter means more wraps means more surface area means more flavor. Obviously, you’d want an ID that is large enough to accommodate the amount of wick you need, but would love some opinions on what you guys prefer and why. :smiley:


I use 2.5-3.5mm ID coils, it varies by the device I’m using them in.
The bigger ID coils i use for my sub ohm rta’s/ rdta’s. The reason for the bigger ID coils i find, you can use more cotton, it wicks faster giving you more juice vaporised per draw and also has bigger surface area. I do space my coils and this helps drastically with any singeing/burning of the wick. This way gives me maximum flavour/vapor production.
The smaller diameter coils i tend to use in my mtl set up’s where the device is not too demanding and doesn’t have to be fed juice at a rapid rate, i still space the smaller coils too.
These set up’s are my preference, I’ve tried closed/contact coils and spaced are far better imo.


The way I look at it the size of what you are wrapping weather it is round wire or a clapton of some design is constant. So 6 wraps of 24 gauge wire at 2mm would be the same width (ie: lead to lead) as that wire wrapped at 3mm. The larger diameter gives you more surface area and room for more cotton.


@Pattie pretty much said exactly what I would have said. I only build on 3 different atty’s and they all will hold a 3mm spaced coil perfectly so that is all I use. I find that size very easy to wick and more than adequate vapor production.


I find with SS wire you have to use a bigger ID to get the ohms you’re looking for


What they all said :grinning:


I also agree with what has already said but no one mentioned space requirements. Larger ID can also mean less wraps. I usually use 3mm ID so the cotton is not squeezed into a small coil hole and therefore I have better juice flow, plus the coil is more compact side to side…


Nice job everybody. It’s mostly all said.

My take or other explanation is preferance and end result. Sometimes when you try a 2.5mm your flavor production isn’t as good.

So you try and rewick and rewick. If it doesn’t work try a 3mm or 2mm. See if that works. Then repeate.

Of course there are limitations on device mod & Atty. but if you got the time through trail and error you find which build works great.

So far I love ss316…but sadly my Kanthol Clapton coil at 2.5mm out performs what I have availble in ss316l in my aromamizer supreme. Tomorrowish I will toss in some of my new ss316 wire I have and give it shot. Probably a build of 2.5mm and a 3.0mm. If neither work it’s back to Kanthol.


I would like to learn how you handle the space coil during the initial pulsing. I tried many times with space coils and during the initial pulsing for the coil, I have to pinch the coil to get rid of hot spots and my spacing collapsed to be a contact coil or worse, sometimes my coil goes out of shape.

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I am not sure what would cause hot spots on a spaced coil. I only use 316L now and have never seen a hot spot. I press and hold the fire button at low wattage until the entire coil turns red, let it cool for a second or 2 and fire the same way a second time and this is what it looks like.


When I am tweaking a new spaced coil, rather than pinching it, I will gently use something thin and flat such as a razor blade between each wrap of the coil to evenly space them. That gets the coil to heat evenly for me. In general I build the coil to the capacity of the juice holes. Its kind of irritating when you have a build deck that will fit a 3.5 mm coil but the juice holes will only support a 2.5 mm coil. But that’s what a Dremel is for :wink:


Strumming them like you would with a guitar helps using ceramic tweezers, while pulsing.


Practice makes perfect. Oddly enough strumming the coil does it magic when you are trying space a Clapton coil. Also, I place the tool in the coil and pull back, up, down…ever so slightly with a light touch.

I do pinch, but it’s a light touch. Pinching from above, as low as I can get, or straight from the middle. My spaced coils don’t always look to pretty but they get the job done and heat from the inside out.


@Pattie pretty much covered it :+1:

Something to add…

My logic is… It’s all about the juice.

…if it’s all about the juice, that means I need as much wick as possible to hold the juice without choking my cotton (leaving dry spots cause it’s too tight/pinched).

…now it’s all about the wick which means I need as much room as possible inside my coil, maximizing surface area without reducing my “ramp-up” time.

…So now it’s all about the coil. To get more surface area but still maintain a low resistance, (current [Amps] is inversely proportional to resistance [Ohms]); I need the thinnest AWG possible that I can work with, without breaking it, and make the fattest coil I can fit in the atty.

I’m still a Green-horn at this building gig but these are my thoughts so far. I’m not a cloud-chaser but “it comes with the territory” when pursuing flavor. The more juice I can vaporize in a pull, the better.

I like to compare to a lantern wick… The bigger the wick and the more you expose to oxygen (fuel for fire), the brighter the light.

[insert big wick jokes here]
No matter what they tell ya… Wick size matters :laughing:

Summation: It’s not really “all” about one thing or another… Juice, wick and coil are congruent. That’s why it’s so damn difficult trying to get that perfect build on a given atty. I just keep rebuilding and rebuilding till I figure the tank out… It’s a labor of love :stuck_out_tongue_winking_eye:



I don’t “pinch” a spaced coil… It’s more push, pull, poke, prod and strum the coil. If it gets out-of-shape just put the coiling tool/screwdriver back in it and straighten 'er out.


^^^^^ exactly that ^^^^^


Since I vape low watts, for 1.5ohm
single coil, 2mm dia, of 30 Kanthal.
7/6 wrap. If I want to live on the edge,
1.2ohm, I go with a 5/4 half wrap.
( pulling a killer 15 watts out of the
unregulated mod! ) Sorry, wrong thread…:confused::slight_smile:

Well as i am stuck on a pretty small deck till my aromamizer supreme arrives, i have been using 2mm ID in the kanger RBA. Big as i can fit with the spaced out

clapton i have in right now(26g/30g). But normally when space allows it i find 2.5 suits me best. Better wicking than the 2ID and since i havent been going too big on the coils i havent felt the need for 3mm yet… Tho once i get the supreme in, i may give it a go.
Ps dont mind the voltage on that pic i just barely mounted it and hadnt turned it down from the .3ohm i had in prior. I run around 3.9v (35ishwatt) with this coil

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My go to wire is 26/32 clapton but i use different id coil in all my tanks. Dual 5 wrap 2mm for the bellus on 40 watts, dual 6 wrap 2.5mm in the diablo on 55 watts and single 6 wrap 3mm in the tube rta on 26 watts. The reason is every tank has a different purpose. Diablo has a huge deck and crazy open air for giant clouds. So it def needs a bigger coil for all that air flow. Yet is a shorty so still decent flavor but only 2ml capacity. So it’s my fun at home tank. The bellus is a semi restricted lung tank with a smaller build deck. So it needs smaller coils but magically still has great flavor. It’s my all around tank. The tube is a single coil shorty with a medium size deck and open air flow. That gives awesome flavor. It’s my out and about tank bc using so few watts no need for extra batteries and all ss means i cant break it. Also id of your coil does equal more wire. If you tied a tread to fit on your pinkie that same tread wouldn’t fit on your thumb… right? Its exactly the same for wire id. More wire means more surface and bigger vapor/flavor.


I have an uncontrollable urge to pinch that coil together lol.