The neck finish on a PET bottle determines how the cap fits, seals, and opens. Pick the wrong one and you get leaks, short shelf life, or a filling line that cannot handle the bottle. Here is a practical guide to the most common finishes.
PCO1810 (28mm Standard)
PCO1810 is a 28mm diameter with a single-start thread profile. It is simple, cost-effective, and widely available from multiple cap suppliers. It works for still water, non-carbonated beverages, and standard food containers. Use it when your product does not need high pressure resistance and you want maximum supply chain flexibility.
PCO1881 (28mm Lightweight)
PCO1881 is also 28mm but with a shorter thread profile than PCO1810. Both the bottle neck and cap use less material, which cuts total package weight and shipping cost. It is compatible with most standard capping equipment. Use it when you are optimizing for weight and cost and your product is still water or low-pressure beverages.
Other Sizes
30mm: Used for sports drinks and wider-mouth applications where easier pouring matters.
25mm: Found in smaller bottles under 330ml and some pharmaceutical or cosmetic containers where a finer neck is preferred.
29mm (ALASKA): Common in certain regional markets and specific beverage categories. Check your target market standards.
38mm, 43mm, 48mm: Used for wide-mouth jars, edible oil containers, and products that need easy access or scooping.
Before You Finalize
Check four things:
- Can you source caps for this finish in your target market?
- Does your filling line support this thread profile?
- Is the opening and closing torque appropriate for your consumers?
- Does it prevent leaks under your product pressure and temperature?
Mold Design Note
HEYAN preform molds use interchangeable neck inserts. This means you can produce different neck finishes with the same mold body — only the insert needs to change. This cuts tooling cost if you plan to offer multiple bottle variants.
Send your target market, cap supplier, and product type. We will recommend the thread standard that fits.
