PYREX CORNING 4321A-500 Glass Neck Round Bottom Boiling 500ML 14/20 Flask

( Brand: Pyrex Corning ), ( Manufacturer Part Number: 4321A-500 ), ( Intended Use/discipline: Biological Laboratory, Dental Laboratory, Medical Laboratory, Microbiological Laboratory, Physical Laboratory ), ( Country Of Origin: United States ), ( Unit Type: Unit ), ( Additional Information: Surplus Laboratory Consumable Supplies )

Review PYREX CORNING Glass 500ml 14/20 Short Neck Round Bottom Boiling Flask

The **Pyrex Corning 4321A-500 500ml 14/20 Neck Round Bottom Boiling Flask** is a precision-engineered laboratory glassware essential for a wide range of chemical, pharmaceutical, and academic applications. Crafted from **borosilicate glass (Type 3.3)**, this flask exemplifies durability, chemical resistance, and thermal stability, making it ideal for demanding experiments involving heating, refluxing, distillation, or solvent evaporation. The **500ml capacity** strikes a balance between practicality and efficiency, accommodating moderate-scale reactions while maintaining ease of handling and visibility. Its **14/20 standard taper ground joint** ensures a secure, leak-proof connection with compatible glassware such as condensers, adapters, or additional flasks, facilitating seamless integration into complex setups. The **round bottom design** optimizes heat distribution during boiling or reflux processes, reducing hot spots and minimizing the risk of thermal stress or breakage. The **smooth, polished surface** not only enhances clarity for monitoring reactions but also resists corrosion from aggressive solvents, acids, or bases, ensuring longevity even with frequent use. Whether employed in synthesis, extraction, or analytical procedures, this flask s **high-temperature resistance (up to 500 C)** and **low thermal expansion coefficient** guarantee reliability under extreme conditions. Its **ergonomic, ribbed neck** provides a secure grip, while the **flat base** allows for stable placement on hot plates or heating mantles. Backed by the legacy of **Corning Pyrex**, a brand synonymous with quality and precision, this flask is a cornerstone of any well-equipped laboratory, offering a perfect blend of functionality, safety, and performance for both novice and experienced chemists.

### **Pros and Cons of Buying a Pyrex Corning 4321A-500 (500 mL, 14/20 Neck, Round Bottom Boiling Flask)**

1. **Durability and Chemical Resistance** Made from borosilicate glass (Type 3.3), this flask is highly resistant to thermal shock, corrosion, and most common laboratory chemicals, making it suitable for a wide range of applications, including heating, refluxing, and distillation.

2. **High-Temperature Stability** Can withstand temperatures up to **500 C**, allowing for safe use in boiling, heating, and even some high-temperature reactions without warping or breaking.

3. **Standard 14/20 Joint Compatibility** The **14/20 ground glass joint** ensures compatibility with a vast array of laboratory glassware, adapters, and accessories, making it versatile for setups requiring reflux, distillation, or reaction vessels.

4. **Even Heating and Boiling** The **round bottom design** promotes uniform heat distribution, reducing hot spots and improving efficiency in boiling and distillation processes.

5. **Long Lifespan** Properly maintained, borosilicate glass flasks like this one can last for decades, making them a cost-effective investment for laboratories and serious hobbyists.

6. **Safety in High-Temperature Applications** Unlike plastic or lower-quality glass, borosilicate does not degrade under prolonged heat, reducing the risk of failure during experiments.

7. **Easy to Clean and Sterilize** Can be cleaned with most laboratory detergents and sterilized via autoclaving (if not damaged), making it ideal for microbiological and chemical work.

8. **Industry Standard** Widely used in academic, industrial, and home laboratory settings, ensuring reliability and ease of sourcing replacement parts or accessories.

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1. **Fragility Compared to Plastic** While borosilicate is durable, it is still glass and can shatter if dropped or subjected to sudden thermal stress (e.g., placing a hot flask in cold water). Care must be taken during handling.

2. **Weight** The glass is heavier than plastic alternatives, which can be cumbersome for frequent use, especially in large quantities or when setting up complex apparatuses.

3. **Cost** More expensive than plastic or lower-grade glassware, though the long-term durability often justifies the initial investment.

4. **Limited Flexibility in Modifications** Unlike plastic, borosilicate glass cannot be easily modified (e.g., drilling holes or sealing with adhesives) without specialized equipment and expertise.

5. **Potential for Contamination** If not properly cleaned, glassware can harbor residues from previous experiments, requiring thorough washing to avoid cross-contamination.

6. **Not Ideal for Extreme Pressure** While strong, it is not designed for high-pressure applications (e.g., pressure reactors). For such uses, specialized glass or metal equipment is required.

7. **Maintenance of Ground Joints** The **14/20 joint** requires periodic cleaning and lubrication with high-vacuum grease to maintain a proper seal, adding slight maintenance overhead.

8. **Limited Availability of Replacements** While common, finding exact replacements (especially for older models) may be difficult if the flask is damaged beyond repair.

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The **Pyrex Corning 4321A-500 (500 mL, 14/20, Round Bottom Boiling Flask)** is an excellent choice for **laboratory work requiring durability, chemical resistance, and high-temperature stability**. Its borosilicate construction ensures reliability in demanding applications, while the **14/20 joint** makes it highly adaptable. However, its **fragility, weight, and higher cost** compared to alternatives may be drawbacks for casual users or those working with minimal budgets.

For **serious chemists, students, or hobbyists** involved in **distillation, reflux, or high-temperature reactions**, this flask is a **highly recommended investment** due to its longevity and performance. For **budget-conscious or low-risk applications**, a plastic or lower-grade glass alternative might suffice, but it lacks the robustness of borosilicate.

- You need a **durable, high-temperature-resistant** vessel for **distillation, reflux, or boiling**.

- You require **standard 14/20 joint compatibility** for laboratory setups.

- You prioritize **long-term reliability** over cost savings.

- You work with **low-temperature or non-corrosive** substances and prefer **lighter, cheaper** options.

- You frequently handle **high-pressure or explosive reactions** (specialized glass or metal equipment is needed).

- You are on a **tight budget** and can tolerate slightly less durability.

For most **serious laboratory applications**, this flask is **highly worth the investment**.

Details:

May show minor signs of use such as light residue or writing. See pictures for details. No chips or cracks noted throughout. GSR veers 1730 GS 9.9.4 1730 Used item in good condition.

part #: 4321a500 prices

• $19.99-$34.99

specifications plasticwarelabsuppy:

• brand: Pyrex Corning
• mpn: 4321a-500
• intended use/discipline: Biological Laboratory, Dental Laboratory, Medical Laboratory, Microbiological Laboratory, Physical Laboratory
• country of origin: United States
• unit type: Unit
• additional information: Surplus Laboratory Consumable Supplies

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• started: February 6, 2026
• sold: 0
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• quantity: 24

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• Medical, Lab Dental Supplies > Glassware Plasticware > Other Medical Lab Glassware
• condition: Used

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