Description
Product Overview
The Karter Scientific Rubber Stoppers size #6 are engineered to meet the rigorous demands of modern laboratory environments. Constructed from high‑grade, chemically resistant rubber, each stopper conforms precisely to the National Bureau of Standards (NBS) specifications, guaranteeing a uniform fit across a wide range of glassware. With a top diameter of 32 mm, a bottom diameter of 26 mm, and a length of 25 mm, these stoppers provide a secure, leak‑free seal that protects samples from contamination and evaporation. The material composition offers excellent resistance to acids, bases, solvents, and temperature fluctuations, making them suitable for both routine assays and specialized research protocols. Packaged in a convenient single‑unit configuration, the 216Q2 model ensures that laboratories can maintain inventory control while minimizing waste.
![[Product front view showing all components]](https://www.imageperfect.store/wp-content/uploads/2026/07/640b0e1970514a53ab3e8af27a7f5b52.jpg)
Usage
These rubber stoppers are ideal for a broad spectrum of laboratory applications, including titration, distillation, filtration, and storage of reagents. Their versatile size #6 fits commonly used Erlenmeyer flasks, beakers, and graduated cylinders, allowing scientists to quickly secure vessels without the need for additional adapters. In educational settings, the stoppers provide a reliable teaching tool for demonstrating proper sealing techniques and safe handling of volatile substances. The stoppers also perform well in quality‑control labs where consistent sealing is critical for reproducibility of analytical results. Whether used in chemistry, biology, environmental testing, or pharmaceutical development, the Karter Scientific stoppers deliver dependable performance that supports accurate data collection and sample integrity.
Why Choose Us
Karter Scientific has a long‑standing reputation for delivering high‑quality laboratory consumables, and the size #6 rubber stoppers are no exception. Each stopper undergoes strict quality‑assurance testing to verify dimensional accuracy, material uniformity, and durability under simulated laboratory conditions. The company’s commitment to compliance with industry standards ensures that every product meets or exceeds NBS specifications, providing confidence to researchers who rely on precise fit and chemical resistance. Additionally, Karter Scientific offers responsive customer support and a straightforward return policy, reinforcing the brand’s dedication to user satisfaction. By choosing these stoppers, laboratories benefit from a combination of proven reliability, consistent manufacturing, and a partner that values scientific excellence.
Key Features
- Premium rubber material resists acids, bases, and solvents for long‑term durability
- Exact NBS dimensions (32 mm top, 26 mm bottom) ensure a tight, leak‑free seal
- Versatile size #6 fits a wide range of common laboratory glassware
- Stable performance across temperature variations and repeated use
- Responsive customer support and hassle‑free return policy for peace of mind
FAQ
What types of chemicals are these stoppers compatible with?
The rubber formulation is designed to resist most laboratory acids, bases, and organic solvents, making it suitable for a broad range of chemical applications.
Can the stoppers be autoclaved for sterilization?
Yes, the stoppers can withstand standard autoclave cycles without deformation, allowing for safe reuse after proper cleaning.
Do the stoppers meet any specific industry standards?
All Karter Scientific size #6 stoppers conform to the National Bureau of Standards (NBS) specifications for rubber laboratory stoppers.
How should I store the stoppers to maintain their integrity?
Store them in a cool, dry place away from direct sunlight and extreme temperatures. Keeping them in their original packaging helps protect them from dust and contamination.
What is the recommended replacement interval for these stoppers?
While the stoppers are highly durable, it is advisable to inspect them regularly for signs of wear or cracking and replace them as needed to ensure optimal sealing performance.






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