Does Your Bottle Match the 18/415 Screw Pump: How to Measure the Neck Size Correctly?

In the precision-driven world of cosmetic and pharmaceutical packaging, a millimetric discrepancy can be the difference between a high-end product and a leaking liability. The 18/415 Screw Pump is a ubiquitous standard for essential oils, serums, and high-viscosity perfumes, yet it remains one of the most frequently mismatched components in the industry. Zhangjiagang XinYe Chemical Sprayer Co., Ltd., founded in 2006, operates from a 100,000 square meter production base equipped with full-auto production and inspection technology. As an ISO9001-2008 certified leader, we understand that achieving a hermetic seal requires rigorous adherence to standardized neck dimensions. Whether you are sourcing a wholesale 18/415 treatment pump for serums or a specialized sprayer, understanding the "18" and the "415" is the first step toward packaging integrity.

Deconstructing the 18/415 Measurement Standard

The nomenclature of a screw pump refers to two distinct measurements defined by the Glass Packaging Institute (GPI) and the Society of the Plastics Industry (SPI). The "18" refers to the nominal outer diameter of the bottle's neck threads in millimeters, while the "415" refers to the thread finish, which dictates the height of the neck and the number of thread turns. According to the 2024-2025 Global Packaging Standards update by the International Organization for Standardization (ISO), precision in thread pitch and "T" dimensions (the outer diameter of the thread) has become increasingly critical as sustainable, thinner-walled glass and plastic bottles enter the market, necessitating tighter tolerances for leak prevention.

Source: ISO 22715:2024 - Cosmetics Packaging and Labeling Standards

Comparing the 18/410 vs. 18/415 Neck Finishes

While both pumps share an 18mm diameter, they are not interchangeable. The 415 finish is significantly taller than the 410, featuring a "long neck" design that allows for more thread engagement. Using an 18/415 pump on an 18/410 bottle will result in an exposed gap, leading to oxidation and leakage.

How to Measure Your Bottle Neck Like an Engineer

To ensure your high viscosity 18/415 screw pump fits perfectly, you must measure the "T" and "E" dimensions using digital calipers. The "T" dimension is the outside diameter including the threads, while the "E" dimension is the outside diameter of the neck tube excluding the threads. Furthermore, the "H" dimension (height from the top of the neck to the shoulder) must accommodate the 415's longer skirt. For B2B buyers sourcing a leak proof 18/415 pump for glass bottles, checking the dip tube length is equally vital; a tube that is too long will curve and obstruct the pump mechanism, while one that is too short leaves product at the bottom.

Measurement Variables: Bottle vs. Closure

A precision 18 415 dispensing pump relies on the interaction between the bottle's land area (the very top surface of the neck) and the pump's internal gasket. If the bottle neck is uneven, even a correctly sized pump will leak.

Material Compatibility and Technical Features

Beyond the fit, the material of the pump components must be compatible with your formulation. At XinYe Chemical Sprayer, our production chain—from aluminum stamping and injection moulding to surface oxidization—ensures that every 18 415 screw pump with aluminum collar provides both aesthetic appeal and chemical resistance. According to reports from the Personal Care Products Council (PCPC), there is a 2025 industry shift toward "metal-free path" pumps to prevent the degradation of sensitive organic serums. Our pumps are designed with high-quality PP and internal springs that are isolated or treated to ensure product purity.

Source: Personal Care Products Council - 2025 Cosmetic Packaging Trends

• Full-Auto Assembly: Ensures consistent spring tension and dosage (typically 0.15cc to 0.25cc) across millions of units.
• Advanced Oxidization: Provides a durable, luxurious finish for 18 415 screw pump with aluminum collar options.
• Complete Chain Production: From raw injection to final automatization, allowing for customized dip tube lengths and colors.
• ISO Certified Quality: Every batch undergoes full-auto inspection to meet survival-grade quality standards.

Frequently Asked Questions (FAQ)

1. Can I use an 18/415 pump on an 18/410 bottle?

No. An 18/415 Screw Pump is designed for a taller neck. On an 18/410 bottle, the pump will bottom out before the gasket seals against the top of the bottle, causing leaks.

2. What is the best way to determine if my serum is "high viscosity"?

If your product has the consistency of a thick gel or heavy oil, a high viscosity 18/415 screw pump with a larger internal valve is required to ensure smooth priming and dispensing without clogging.

3. Why should I choose an 18 415 screw pump with aluminum collar?

The aluminum collar provides a premium "prestige" look and adds structural rigidity to the screw mechanism, making it ideal for luxury cosmetic lines where tactile quality is essential.

4. Does XinYe provide custom dip tube lengths for wholesale orders?

Yes. For wholesale 18/415 treatment pump for serums orders, we customize the dip tube length to match your specific bottle height, ensuring maximum product evacuation.

5. How do I verify the "H" dimension of my bottle?

Measure from the very top of the bottle neck down to the point where the neck meets the bottle shoulder. For a 415 finish, this measurement is typically around 18mm.