Bottle Neck Finishes 24/410 vs 28/410: Match Cap to Closure

The neck finish is the smallest spec with the biggest consequences — it decides every closure you can use. The 24/410 vs 28/410 decision.

What the numbers mean

24/410 means a 24 mm neck diameter with a 410 thread standard; 28/410 is 28 mm. The thread standard must match the closure or it will not seal.

24/410 use

Treatment pumps, droppers, disc-tops and screw caps — common on 30–150 ml bottles where a precise, small dose matters.

28/410 use

Lotion pumps, triggers and wider dispensing — common on 200 ml and larger bottles for controlled, higher-volume output.

Related: cosmetic bottles.

How to read a neck finish code

A neck finish has three parts, and they are not interchangeable. The first number is the neck diameter in millimetres, measured across the outside of the threads. The number after the slash is the thread standard — the pitch, thread depth and cap height that the closure industry builds to. Some suppliers add a letter for thread style, so 24/410 and 24/415 share the same 24 mm diameter but take different caps.

The practical rule: the diameter decides what physically fits; the standard decides what actually seals. Two closures with the same diameter and a different standard look identical in a catalogue photo, and only one of them will screw on. This is the single most expensive misunderstanding in bottle sourcing, because it is usually discovered at the filling line.

24/410 vs 28/410 at a glance

Which closure goes with which neck

The closure usually decides the neck, not the other way round. Work backwards from how the product is used:

• Dropper or pipette — 18/415 or 20/410 on 15–50 ml. The dropper bulb and glass length are matched to the bottle height, so confirm both together.
• Treatment pump — 20/410 or 24/410 on 30–100 ml. Airless versions use a different neck again, so never assume a pump is neck-agnostic.
• Disc-top — 24/410 or 28/410. The disc diameter sets the flow, so a 28/410 disc-top delivers noticeably more per press than a 24/410.
• Lotion pump — 24/410 or 28/410, with the dip tube cut to the bottle’s internal depth. A tube that misses the bottom leaves product behind; one that is too long curls and blocks.
• Trigger sprayer — 28/410 or 28/415 on 200 ml and up, generally for household and car care rather than leave-on cosmetics.
• Screw cap or liner — any diameter, but the liner is chosen for the formula: an EPE liner for aqueous products, a foil or induction seal where tamper evidence matters.

Neck finish and the filling line

Neck finish affects throughput, not just fit. A wider neck fills faster and is easier to target, which matters at 500 ml and above. Narrow necks reduce the fill aperture and slow automatic fillers, and they need a more accurate nozzle to avoid product on the thread — residue on the thread is a common cause of a cap that will not torque cleanly.

If you fill in-house, check the neck against your filler head and capping chuck before the mold is cut. If your co-packer fills, send them the neck spec, not just the bottle capacity, and ask for their capping torque range.

Neck finishes we tool most often

• Narrow: 18/415, 20/410 — droppers, oils and small treatment formats.
• Mid: 24/410, 24/415, 28/410, 28/415 — the workhorses for skincare and personal care.
• Wide-mouth cosmetic: 32/410, 33/400 — thicker formulas, masks and scrubs.
• Technical and industrial: 38/400, 43/410 and larger where a big aperture or a wide cap is required.
• Foam pump: 40/410 and 43 mm seats — foamers are a separate family and cannot be swapped onto a 410 thread.
• Wide-mouth jars and caps: 54 mm, 58 mm and 68 mm — cream jars and bulk formats.

All of the above sit on stock molds, so a new bottle in an existing neck usually means decoration and colour only, not a new tool.

How to confirm a neck before you order

1. Measure the current bottle if you have one: outside thread diameter across the widest point, with callipers, in millimetres.
2. Identify the standard by comparing against a closure that already fits, if you have a sample.
3. Send the neck code and a photo of the neck to your supplier, along with the closure you intend to use.
4. Ask for a closure sample on the same neck before you commit to volume.
5. Confirm on a pre-production sample, and only then release the full run.

Where the neck sits in your cost picture

Choosing a neck that already exists on a stock mold keeps your tooling cost at zero and shortens lead time, because nothing new has to be cut. A custom neck only makes sense when it enables a closure or a dose that no standard option delivers — and even then, a standard 24/410 or 28/410 with a different closure is usually the faster route to market.

For orders that mix bottles and closures, sourcing both from one supplier removes the risk of a thread mismatch entirely, because the bottle and the closure are checked against each other at the factory rather than in two different warehouses.

Choosing between 24/410 and 28/410 for a new product

Starting from a blank brief, this sequence resolves the choice quickly:

1. Decide the dose. Fine, metered doses point to 24/410; a generous pour or pump points to 28/410.
2. Match the volume. Under 150 ml, 24/410 keeps the proportions right; over 200 ml, a 24 mm neck starts to look narrow against the shoulder.
3. Check the closure exists. Most treatment pumps and droppers are built for 24/410; most lotion pumps and triggers for 28/410.
4. Confirm with a sample before the artwork is finalised, because the cap diameter changes the visual balance of the whole bottle.

If a formula could work with either, the tie-breaker is almost always the closure family you need — not the bottle itself.

Common neck finish mistakes

• Ordering caps before the neck is confirmed. The closure is the last thing to buy, not the first.
• Assuming 410 and 415 are interchangeable. Same diameter, different thread — they are not.
• Mixing suppliers by default. A bottle from one factory and a pump from another is a fit risk you carry yourself.
• Ignoring the dip tube. A pump that fits the neck can still leave product behind if the tube length is wrong.
• Skipping the physical sample. A neck code on a drawing has no feel; a sample does.

Questions buyers ask us most

Which neck for a serum?

20/410 or 24/410 for droppers and treatment pumps on small bottles.

What happens with a mismatched neck?

The closure will not seal or fit — always confirm the neck finish before sourcing caps and pumps.

Talk to the team before you lock the mold. See the catalog or message us and we will match your formula to a bottle that ships clean.