Perfume Bottle Neck Finish Sizes, FEA Codes & Thread Standards

A perfume bottle neck finish is the standardized top section of a fragrance bottle — its exact diameter, thread pattern, and height — that determines which spray pump, crimp collar, or cap will physically fit and seal onto it. Fragrance packaging relies on two dominant sizing systems: FEA crimp sizes (commonly 10mm, 12mm, 15mm, 18mm, and 20mm) for spray pumps, and GPI/SPI thread codes (400, 410, 415) for screw closures. For brands, traders, and filling factories sourcing glass bottles, matching the correct neck finish to the correct closure isn’t a minor spec detail — it’s the difference between a sealed, sellable product and a warehouse full of leaking, mismatched inventory.

This guide breaks down every dimension, standard, and sizing code you need to specify a perfume bottle neck finish correctly the first time, so your pumps, caps, and glass actually work together on the line.

1. What Is a Perfume Bottle Neck Finish and Why It Matters

Definition of Bottle Neck Finish

A neck finish is the “connector” at the top of the bottle — the shape, diameter, and thread (or absence of thread) that determines what closure can physically attach to it. It works the same way a phone charging port does: you can’t plug a USB-C cable into a Lightning port, and you can’t crimp an 18mm pump onto a 15mm neck.

Every neck finish is defined by five core dimensions that packaging engineers refer to as T, E, I, H, and S — covered in full detail in the next section. In short, these numbers describe the outer thread diameter, the smooth neck diameter below the threads, the opening size, the total height of the finish, and where the threads begin. A mismatch in any one of these means the pump won’t seat, won’t seal, or won’t crimp correctly.

Importance in Fragrance Packaging and Leak Prevention

Perfume is mostly alcohol, and alcohol is one of the most aggressive liquids to seal against. It evaporates fast and finds the smallest gap in a closure within days, not months. A neck finish that’s off by even a fraction of a millimeter can cause slow leakage, a telltale scent seeping through a shipping carton, or a bottle that’s already lost volume by the time a customer opens it.

Cutting corners on neck finish tolerance to save a few cents per unit almost always backfires. The sealing surface — the top rim where a crimp collar or cap gasket makes contact — has to be dimensionally consistent across every bottle in a batch, or a percentage of the run will leak. Once a retailer or distributor receives a shipment with leak complaints, that relationship gets much harder to repair.

How Neck Finish Impacts Spray Pump Compatibility

A spray pump isn’t universal. Its collar is manufactured to grip one specific outer neck diameter. The most widely used fine-fragrance standard, FEA sizing (from the French “Flacon Embout Atome”), is not interchangeable between sizes . An FEA15 pump will not seat on an FEA18 neck — forcing it either cracks the glass shoulder or leaves a gap that seeps.

This becomes especially important when bottles and pumps are sourced from two different factories, which is standard practice in this industry. Glass mills specialize in glass; pump manufacturers specialize in pumps. Confirming the collar size matches the neck spec is the buyer’s responsibility before committing to a production run.

2. How to Measure Perfume Bottle Neck Finish Dimensions

The Key Dimensions (T, E, I, H, and S Measurements)

These five letters appear on every glass mill’s spec drawing:

• T (Thread Diameter)— the outermost measurement across the threads, which must match the closure’s inner thread diameter
• E (Neck Outside Diameter)— the smooth section just below the threads, used to calculate thread depth
• I (Inside Diameter)— the size of the bottle opening, relevant for filling equipment and dip tube clearance
• H (Finish Height)— the total vertical length of the neck finish, from the top sealing surface to the base of the finish
• S (Thread Start)— the distance from the top sealing surface to where the first thread begins, affecting cap seating

On a standard 410 thread profile, an 18mm finish typically measures T at roughly 0.694 inches (about 17.6mm) with a tolerance of ±0.010 inches, and E around 0.610 inches . A 20mm finish on the same profile increases T to about 0.773 inches and E to about 0.689 inches . These tolerances look small on paper, but on a filling line running thousands of bottles an hour, that tolerance window separates a smooth run from a QC problem.

Tools Required for Accurate Neck Measurement

• A digital caliper accurate to 0.01mm, for measuring T and E
• A thread pitch gauge, or simply counting thread turns to identify the profile (400, 410, 415)
• A depth gauge or the caliper’s depth probe for H and S
• A go/no-go gauge for high-volume incoming QC, faster than manual measurement on every unit
• Sample closures (pump, crimp collar, screw cap) on hand for physical fit testing

Step-by-Step Guide to Measuring Bottle Threads and Necks

1. Measure T across the outermost edge of the threads, straight through the center to the opposite outer edge — not just the diameter of the hole
2. Count the thread turns: one full turn typically indicates a 400 profile, 1.5 turns a 410, and two tighter turns a 415
3. Measure E just below the last thread, on the smooth part of the neck
4. Measure H from the top sealing surface down to the base of the finish
5. Measure S from the top surface down to where the first thread begins
6. Cross-check the numbers against a standard GPI/SPI or FEA chart to confirm the finish code
7. Run a physical trial fit with an actual pump or cap sample before finalizing a purchase order

3. Common Types of Perfume Bottle Neck Finishes

Crimp Neck Finishes (FEA Standards)

Crimp finishes dominate fine fragrance packaging. A crimping machine presses the spray pump’s metal skirt tightly around a specially shaped neck to lock it in place . FEA sizing describes the collar’s inner diameter in millimeters:

Crimp finishes give a genuinely secure, tamper-evident seal — once crimped, the pump won’t come off without deforming it, which matters for a liquid that’s mostly alcohol. The tradeoff is that crimping requires dedicated equipment. Most contract filling factories already have crimping heads for common sizes, but unusual sizes need equipment confirmation before committing to bottle tooling.

Screw Neck Finishes (GPI/SPI Thread Standards)

Screw finishes use continuous threads following GPI (Glass Packaging Institute) or SPI (Society of the Plastics Industry) standards. These are less common in prestige fine fragrance but common in body mists, hair mists, and lower-cost fragrance lines where a threaded cap or continuous-thread sprayer fits the format better.

Screw closures offer flexibility and reusability — they can be removed and reapplied without damaging the neck, which matters for refill programs or repeated cap use. The thread profile codes (400, 410, 415) indicate the number of thread turns and finish height, detailed in the next section.

Snap-On and Friction Fit Neck Finishes

Snap-on finishes rely on friction rather than threads or crimping — the cap simply pushes down and locks onto a shaped lip. These typically appear as outer decorative caps sitting over a crimped pump rather than as the primary sealing mechanism. They apply quickly on automated lines and give a clean appearance, but they aren’t relied on for the primary liquid seal in fine fragrance — that job belongs to the crimp or thread underneath.

4. Standard Perfume Bottle Neck Finish Sizes

13mm, 15mm, 18mm, and 20mm Crimp Finishes

These four sizes cover the majority of fragrance bottles on the market. Sticking to one of these four sizes when sourcing stock bottles makes sourcing dramatically easier — pumps, collars, and overcaps in these sizes are widely stocked, meaning shorter lead times and lower minimum order quantities than custom sizes.

Crimping does allow slightly more size tolerance than threaded systems, since the crimping process compresses metal around the neck. That flexibility has limits, though — a handheld crimper set for 15mm will not properly seal a 13mm or 20mm neck. Different sizes generally require different crimping heads or an adjustable crimping tool.

Common Thread Styles (400, 410, and 415 Profiles)

For screw and continuous-thread finishes, the second number in a sizing code indicates the thread style :

• 400— one full thread turn, common on jars and standard caps
• 410— one and a half thread turns, common on vials and smaller containers
• 415— two thread turns, narrower and on a taller neck than the 410
• 425— buttress finish with thicker threads and a top bead, common on jugs
• 430— lug finish with non-continuous threads, typically an economy jug style

A 415 finish and a 410 finish can look similar at a glance, but the 415’s threads are thinner and its neck sits taller, which is why measuring rather than estimating by eye matters .

Understanding Size Designation Codes (e.g., 18/415, FEA 15)

Combining diameter and thread style produces the sizing code. An “18-415” bottle has an 18mm thread diameter with a 415 (two narrow turns, tall) thread profile . A “20-410” has a 20mm diameter with 1.5 thread turns .

For crimp closures, “FEA 15” simply means a 15mm crimp collar diameter — there’s no separate thread code, since there’s no thread . Always confirm which system a factory or component supplier is quoting in. Confusion between an FEA-sized quote and a GPI/SPI-sized quote under the same “18mm” label is a common and costly miscommunication.

5. Choosing the Right Neck Finish and Closure for Your Fragrance

Matching Pumps, Caps, and Collars to Neck Finishes

Get the FEA or GPI/SPI collar size directly from the bottle supplier’s technical drawing — never estimate it from a photo or a rough measurement . Bottle mills produce technical drawings with exact T/E/I/H/S values specifically so that document can travel with every quote request sent to a pump or closure supplier.

Before locking in components, confirm:

• The dip tube length against the bottle’s interior height — it should sit within about 3–5mm of the bottle base to keep drawing liquid when the bottle is nearly empty
• Dosage per spray matches the formula’s viscosity and the brand’s desired mist quality (0.08ml to 0.12ml is a common range for eau de parfum)
• Collar material and finish (aluminum vs. plastic, matte vs. shiny) matches the overcap design
• The overcap or snap-on decorative cap clears the pump’s actuator height once assembled — a common fit issue that only surfaces at final assembly

Testing Fit, Torque, and Sealing Integrity

Fit testing should never happen for the first time on a full production line. Before committing to a full order, request a pilot batch and run real tests:

• Torque testingfor screw closures measures the rotational force needed to apply and remove the cap, checking that it falls within a window where the seal holds during handling but the cap still opens normally . Standard practice tests immediately after capping and again 24 hours later, since torque settles as components relax .
• Vacuum leak testingfills the bottle with dyed liquid, places it in a vacuum chamber, and watches for dye escaping around the pump or cap as pressure drops — a fast way to catch a bad seal before it reaches a customer .
• Inversion testingfills and caps the bottle, then leaves it upside down or on its side for 24 hours to catch slow leaks a quick check would miss .

Testing a handful of units, not just one, is essential — variation across a production batch is exactly what this process is meant to catch.

Avoiding Common Bottling and Sealing Mistakes

• Assuming “18mm” always means the same thing across FEA and GPI/SPI systems — always confirm which standard is being quoted
• Skipping the physical fit test because the numbers on paper “look right” — paper specs and real-world tolerance stacking aren’t always identical
• Using a single crimping head across multiple neck sizes without confirming it’s adjustable for that size
• Overlooking nicks or roundness defects on the sealing surface, which cause leaks even when every other dimension is within spec
• Ordering full production volume before running a pilot batch through torque and leak testing

I found strong supporting data on lead times, MOQ costs, mismatch risk (a 0.2mm gap can already cause leakage), and pilot batch structure. Let me expand that closing section with real cost/timeline context and a concrete pre-order checklist.

6. A Small Detail That Decides a Lot

Here’s an uncomfortable truth about neck finishes: they will never be the part of a fragrance launch anyone gets excited about. Nobody puts a T-dimension on a moodboard. Nobody’s brand deck has a slide about crimp tolerance. And yet, walk into almost any post-mortem on a packaging disaster in this industry, and the root cause traces back to the same overlooked detail — a neck finish spec that got assumed instead of verified.

The math on why this keeps happening isn’t complicated. Bottle sourcing already involves enough moving parts — mold development, glass production scheduling, surface decoration, component supply, quality control, and shipping — that lead times for custom fragrance bottles routinely stretch from four to sixteen weeks depending on complexity. When bottles and pumps come from two separate factories, which is standard practice, the neck-finish confirmation is often the one step that gets rushed or skipped entirely under deadline pressure. And the tolerance for error is smaller than most people expect: industry quality teams have flagged that even a 0.2mm mismatch between a bottle neck and a pump collar is enough to create what one packaging engineer bluntly called “a highway for leakage”. That’s not a big visible gap you’d catch by eye on the factory floor — it’s a fraction of a millimeter, invisible until the bottle is filled, capped, and sitting in a warehouse or a shipping container.

What Actually Goes Wrong When This Gets Skipped

The failure pattern tends to look the same across brands, regardless of size or budget. It usually starts with sourcing bottles and pumps as separate line items rather than as a matched set, because one supplier had a better price or faster sample turnaround on one component. That decision on its own isn’t wrong — plenty of experienced buyers mix and match suppliers successfully. The problem shows up when nobody cross-checks the actual technical drawings against each other before placing the bulk order, relying instead on a verbal confirmation, a rough label like “18mm,” or an assumption that “standard sizing” means the same thing to both factories.

It rarely surfaces immediately. Samples might look fine sitting on a shelf, uncapped, in a showroom. The real test only happens once the bottle is filled with actual product, capped or crimped at production speed, and put through the stress of a real shipping and handling cycle — vibration, temperature swings, pressure changes in cargo holds. That’s exactly when a marginal mismatch turns into a support ticket, a returned pallet, or a listing pulled from a retailer’s shelf. And by that point, the cost of the mistake isn’t just replacement components — it’s lost shelf time, damaged retailer trust, and in some cases an entire bulk order that has to be reworked or scrapped.

The Fix Is Cheaper Than the Alternative

This is why the pre-order checklist matters so much more than it seems to, especially for anyone new to sourcing fragrance packaging:

• Request the bottle supplier’s technical drawing with exact T, E, I, H, and S values in writing, not a verbal spec or a generic product listing
• Send that exact drawing to the pump or closure supplier and ask them to confirm fit against their own collar or thread spec, in writing, before quoting a bulk price
• Clarify explicitly which sizing system is being used — FEA collar diameter and GPI/SPI thread diameter can both get shortened to “18mm” in casual conversation, and that ambiguity alone causes a large share of mismatch complaints
• Never treat a sample that “looks right” uncapped as proof of fit — the only real test is filling, capping or crimping, and running the assembled unit through basic stress conditions

A pilot batch is the natural checkpoint for all of this, and it’s worth treating as a non-negotiable step rather than an optional nice-to-have. A properly run pilot isn’t just a handful of bottles filled by hand for a photo — it’s a small, controlled run on the actual filling line, at production speed, using the actual bottles, pumps, and caps you intend to buy in bulk. That’s the only setting where a marginal neck-finish mismatch reliably shows up before it becomes a five-figure problem. During that pilot, the checks that matter most are the ones covered earlier in this guide — torque testing, vacuum leak testing, and inversion testing — plus a simple visual and functional pass on a random sample pulled from the line, not just the first few units off the top of the batch.

The cost comparison makes the case on its own. A pilot run adds a modest amount of time and a relatively small fee on top of a project’s timeline. A full bulk order of mismatched bottles and pumps, by contrast, means the cost of the components themselves, the freight to get them to a warehouse, the freight to potentially return or rework them, the cost of expedited replacement components, and — often the most expensive line item of all — the delay to a launch date that may already be tied to a retail commitment, a marketing campaign, or a seasonal selling window. Twenty thousand units sitting in a warehouse because a collar didn’t match a neck isn’t just an inventory problem. It’s lost weeks that don’t come back.

Building This Into a Repeatable Process

For anyone sourcing fragrance packaging regularly rather than as a one-off project, the goal should be turning this verification step into a standing part of the procurement workflow, not a one-time lesson learned the hard way. That means keeping a reference file of confirmed, working neck-finish and closure pairings for suppliers you’ve used successfully, requiring written spec confirmation as a standard line item on every purchase order regardless of how “standard” a size seems, and building a short pilot-batch window into every project timeline from the start rather than treating it as a step to cut when deadlines get tight.

None of this is complicated engineering. It’s mostly discipline — asking for the drawing, checking it against the other component, and testing the assembled unit before money commits to volume. But that discipline is exactly what separates a smooth production run from the kind of phone call nobody wants to make, explaining to a client why their launch just got pushed back a month over a spec that could have been confirmed in a single email exchange.