Walk into any dabbing community today and ask what size banger people are running — the answer is almost always 25mm. The market has shifted decisively over the last few years, and if you're buying a quartz banger in 2025, chances are high it's a 25mm bucket paired with an axial-style coil. But that doesn't mean 20mm is dead — it just means you need to understand what each size is actually designed to do before you spend money on the wrong coil. Here's the full breakdown.

First: The Two Things You're Actually Choosing

When people talk about "20mm vs 25mm coils," they're usually conflating two separate decisions into one. The size (20mm or 25mm) refers to the diameter of the coil opening. But the shape of the coil — barrel vs axial — is equally important, and the two decisions are closely linked.

Barrel coils are cylindrical and wrap around the sides of the banger neck. They heat the sidewall of the bucket but don't cover the bottom. They're held in place by a side arm on the banger or a silicone coil holder.

Axial coils are bucket-shaped — they wrap around both the sides and completely cover the bottom of the banger. They're secured by a cotter pin or o-clamp attached to a small quartz rod extending from the base of the banger. This is the design that has become the modern standard.

Understanding this distinction is key because the two coil types aren't interchangeable — they require completely different banger designs to work correctly.

Why 25mm Axial Has Become the Market Standard\

The shift to 25mm axial setups happened for good reasons. A 25mm bucket gives you more surface area to work with, which means more even vaporization, better concentrate distribution, and the ability to use terp pearls and spinner carb caps effectively. The axial coil design compounds this by heating both the bottom and the walls simultaneously, delivering faster, more even heat across the entire bucket surface.

The result is a setup that performs noticeably better for low-temp dabbing — the style most serious dabbers prefer for maximum flavor. Because the entire bucket is heated evenly from all sides, concentrates vaporize uniformly instead of pooling in the center or scorching in one spot.

The o-clamp and cotter pin mounting system is also more secure than a side-arm barrel setup. The coil locks onto the banger with no risk of slipping during a session, which matters when you're working with a nail sitting at 500°F.

Where 20mm Barrel Coils Still Make Sense

The 20mm barrel coil hasn't disappeared — it's just found its natural home. Fogging Fun's starter enail kits ship with a 20mm barrel coil, and for good reason: barrel coils are beginner-friendly, widely compatible with titanium nails, and offer a slightly different heat profile that some experienced dabbers actually prefer.

Because a barrel coil heats the sidewalls more than the bottom, the bottom of the bucket stays comparatively cooler during a dab. This creates a slower, less aggressive vaporization process that some users find preserves terpenes more gently than the intense bottom-up heat of an axial coil. It's a real consideration if you're running very flavorful live resin or rosin at low temperatures and want every compound to activate gradually.

The 20mm barrel coil is also the right choice if you're using a titanium nail. Most titanium nails don't have the quartz rod base that an axial coil requires for mounting — they work with a barrel coil wrapping the neck of the nail instead. If you're running the universal titanium nail included in many Fogging Fun starter kits, the 20mm barrel coil is your match.

Side-by-Side: Which Coil for Which Setup

Heat-Up Time: Does Size Actually Matter?

In general, a 20mm coil reaches target temperature slightly faster than a 25mm because there's less total wire and a smaller surface area to heat. In practice the difference is around 15–30 seconds on a quality PID controller — noticeable but not dramatic.

What matters far more than size is coil type. An axial coil, regardless of diameter, heats up faster than a barrel coil of the same size because it has more contact points with the banger surface. So a 25mm axial coil will typically heat up as fast as or faster than a 20mm barrel coil, even though it's technically the larger component.

The takeaway: don't choose your coil size based on heat-up speed. Choose it based on what your banger requires, and the heat-up performance will follow naturally from that correct pairing.

How to Tell Which Coil Your Banger Needs

If you're not sure which coil style and size your banger requires, look at the bottom of the bucket.

If there's a short quartz rod sticking out from the base, your banger is designed for an axial coil. The coil slides over the banger and the rod inserts into the center hole of the axial coil, then a cotter pin or o-clamp locks it in place. Measure the diameter of the bucket bottom — that's your coil size. A 25mm bucket needs a 25mm axial coil.

If there's a side arm extending horizontally from the neck, your banger is designed for a barrel coil. The coil wraps around the neck and the arm holds it in place. Most of these setups are 20mm.

If there's neither, you're looking at a standard torch banger not originally designed for enail use. This used to mean your only option was replacing the banger entirely — but the industry has caught up. The cobra coil (also called a deep axial or deep dish coil) is a newer coil design specifically developed to work with standard torch-style bangers that have no quartz rod or side arm. The cobra coil wraps deeply around the outside of the bucket, gripping it securely without needing a mounting pin, which means you can convert almost any torch banger into an enail-compatible setup without buying new glass.

A quick measurement trick: a standard US quarter coin is almost exactly 25mm in diameter, and a penny is close to 20mm. Hold one against the bottom of your banger bucket to get an instant rough size check before ordering.

Compatibility With Fogging Fun Products

Fogging Fun's complete enail kits currently ship with a 20mm barrel coil and a universal titanium nail — a pairing that works reliably out of the box for beginners and delivers consistent results across a wide range of temperatures. If you're starting fresh, this setup is a solid foundation.

If you're upgrading to a 25mm quartz banger — which, given where the market has gone, is a very likely next step for anyone looking to improve flavor and low-temp performance — you'll want to pair it with a compatible 25mm axial coil. Check the Fogging Fun enail coil collection for current coil options, and if you're building a new setup from the ground up, the complete enail kits give you everything you need to get started before upgrading individual components later.

Not sure whether your specific banger and coil are a match? Reach out at cs@foggingfun.com with a photo of your banger base — the team can confirm compatibility in one reply.

The Bottom Line

If you're running a modern 25mm quartz banger, you need a 25mm axial coil — full stop. That's what the banger is designed for, and that's the combination that delivers the low-temp, full-flavor performance that makes quartz bangers worth using in the first place. If you're on a titanium nail or a beginner setup, the 20mm barrel coil does exactly what it needs to do and does it reliably. Know what you have, match the coil to the banger design, and the rest takes care of itself.