PYREX 55640-250 Volumetric Flask Actinic Stopper Glass 250ML

( Brand: Pyrex ), ( Manufacturer Part Number: 55640-250 ), ( Part Type: Stopper )

Review PYREX Volumetric Flask Low Actinic 250ml Class Stopper New Red Glass

The **Pyrex 55640-250 Volumetric Flask with Actinic Stopper (250 mL, Glass)** is a precision-engineered laboratory glassware essential for accurate and reliable volumetric measurements in scientific research, pharmaceutical development, and analytical chemistry. Crafted from high-quality borosilicate glass, this flask exemplifies durability and resistance to thermal shock, ensuring stability across a wide range of temperatures from cryogenic conditions to high-heat applications. The **250 mL capacity** adheres to stringent international standards, providing precise volume markings that conform to Class A tolerances, making it ideal for titrations, dilutions, and standard solution preparations where exact measurements are critical. The **actinic (amber) glass stopper** not only prevents light-induced degradation of sensitive compounds such as vitamins, pharmaceuticals, or photolabile reagents but also minimizes evaporation, preserving sample integrity over extended periods. The ground-glass joint ensures a secure, leak-proof seal, while the smooth, polished surface facilitates easy cleaning and sterilization, whether by autoclaving, ultrasonic bath, or manual scrubbing. Designed with both functionality and safety in mind, this flask features a wide mouth for convenient filling and pouring, reducing the risk of spills or contamination. Whether used in a research lab, educational setting, or industrial quality control facility, the **Pyrex 55640-250 Volumetric Flask** delivers uncompromising accuracy, chemical resistance, and long-term reliability, making it an indispensable tool for scientists and technicians who demand precision in their work.

**Pros and Cons of buying a Pyrex 55640-250 Volumetric Flask (Actinic, 250 mL, Glass Stopper)**

1. **Precision and Accuracy** Volumetric flasks are designed for precise liquid measurements, making them ideal for laboratory work requiring exact volumes, such as titrations, dilutions, or standard solutions.

2. **Durability** Pyrex glass is known for its resistance to thermal shock, meaning it can withstand rapid temperature changes without cracking, which is useful in various laboratory conditions.

3. **Chemical Resistance** The borosilicate glass composition of Pyrex makes it resistant to most acids, bases, and organic solvents, ensuring longevity in harsh chemical environments.

4. **Actinic (UV-Transmitting) Property** The "actinic" designation means the flask allows ultraviolet light to pass through, which is beneficial for photochemical reactions or UV spectroscopy applications.

5. **Standardized Sizes** The 250 mL size is a common laboratory volume, making it compatible with many standard laboratory procedures and equipment.

6. **Glass Stopper** The included glass stopper helps prevent contamination and spills, improving safety and convenience during use.

7. **Long-Term Reliability** High-quality glassware like Pyrex is built to last for years with proper care, making it a cost-effective investment for frequent use.

1. **Fragility** Despite its durability, glassware is still prone to breakage if dropped or mishandled, which can be a safety hazard in busy labs.

2. **Weight** Glass flasks are heavier than plastic alternatives, which may make them less convenient for frequent handling or transport.

3. **Cleaning and Maintenance** Glass requires thorough cleaning with detergents and sometimes ultrasonic baths to remove residues, which can be time-consuming.

4. **Limited Reusability in Some Cases** If the flask is exposed to highly corrosive substances or extreme conditions, it may degrade over time, reducing its lifespan.

5. **Cost** While Pyrex is durable, high-quality glassware can be more expensive upfront compared to disposable plastic alternatives, though it often pays off in the long run.

6. **Not Ideal for High-Pressure Applications** Unlike some plastic or metal alternatives, glass flasks are not suitable for high-pressure environments or autoclaving (unless specifically labeled as autoclave-safe).

7. **Potential for Staining or Etching** Prolonged exposure to certain chemicals or improper cleaning can cause staining or etching on the glass surface, affecting accuracy.

The Pyrex 55640-250 volumetric flask is a high-quality, precision tool well-suited for laboratories requiring accurate liquid measurements, chemical resistance, and UV transparency. Its durability and reliability make it a valuable asset for routine analytical work, titrations, and photochemical experiments. However, its fragility, weight, and maintenance requirements may pose challenges in certain environments, particularly where ease of use or disposable alternatives are preferred.

This flask is **highly recommended** for laboratories that prioritize precision, chemical compatibility, and long-term durability. It is particularly well-suited for:

- General chemistry laboratories performing titrations or dilutions.

- Research settings involving photochemical reactions or UV-sensitive experiments.

- Educational institutions where accuracy and reusability are essential.

If the primary use involves low-risk, routine procedures and cost is a major concern, consider evaluating disposable plastic alternatives or lower-cost glass options. However, for demanding applications where reliability and chemical resistance are critical, the Pyrex volumetric flask remains an excellent choice. Always ensure proper handling, cleaning, and storage to maximize its lifespan.

Details:

Sharp and clear graduation line.: height w/ Stopper, 250mm. These are shown in the last photo at bottom right corner. Our previously used glassware is cleaned before sale.

Note that there is a pair of what appears to be scratches from manufacture towards the upper area body. Combined Shipping: When quantities greater than one are entered into a listings shipping calculator, it will likely display charge that is higher what actually be charged. Even brand-new glassware should be cleaned as it is typically slightly alkaline from manufacture. Marked with a lot number.

However, all glassware should be carefully cleaned before use. These two lines are believed to be scratches due the fact that they can easily felt on outer glass surface. Note that if the item was sealed, it cannot be opened or tampered with. The body features large, easily visible block characters.

Please see the shipping calculator for cost to send this item alone. Burst test shipping boxes for maximum glass protection. Includes an unused ST16 hollow barrel low-actinic stopper. Many chemical and laboratory processes are dangerous.

Class A Pyrex Volumetric Flask, Red 250mL / TC 20 C. This happens because the system adds all weights and packaging fees together. Please feel free to request a quotation for any combined shipping costs, be sure include your zip code. The tolerance is /- 0.12mL.

It cannot account for all the variables involved in multiple item orders.

part #: 55640250 prices

• $51.05-$189.99

specifications plasticwarelabsuppy:

• brand: Pyrex
• mpn: 55640-250
• part type: Stopper

seller plasticwarelabsuppy:

• # reviews: 3166
• rating: 100.0%
• city: Santa Maria, California

general plasticwarelabsuppy:

• condition: New Open box
• Medical, Lab Dental Supplies > Glassware Plasticware > Other Medical Lab Glassware

shipping plasticwarelabsuppy:

• type: Calculated
• class: Standard, Expedited
• cost: $13.45
• service: USPS Ground Advantage, USPS Priority Mail
• transit: 3-8 Days
• carrier: USPS

returns plasticwarelabsuppy:

• policy: No Returns

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offer plasticwarelabsuppy:

• sold: 0
• best offers: True
• availability: In Stock
• quantity: 1
• started: March 2, 2026
• options: Ship-to-home

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