Assorted PYREX VWR KIMAX Volumetric Flask Class A 25 ml with Stopper No. 9 - Total of 8 Flasks

Assorted Brand Class A Glass Volumetric Flasks, 25 mL with No. 9 Standard Taper Stoppers (PYREX® / VWR® / KIMAX®)

This Assorted Brand 25 mL Class A Volumetric Flask listing delivers high-precision, laboratory-grade volumetric glassware sourced from leading scientific manufacturers, including Corning® PYREX®, VWR® Collection, and Kimble® KIMAX®. Engineered to meet strict ASTM E288 and ISO 1042 compliance parameters, these Class A flasks are calibrated "To Contain" (TC) a precise liquid volume of 25 mL at an ambient temperature baseline of 20°C. Each flask features a heavy-duty, uniform neck profile topped with a ground-glass **No. 9 Standard Taper ($TS$) outer joint** and comes equipped with a matching chemical-resistant glass or high-density polymer pennyhead stopper. Sourced from verified laboratory equipment overstocks and asset liquidations, these assorted Class A components provide exceptional thermal and chemical resistance for critical analytical solution compounding, serial dilutions, and calibration standard preparations.

Technical Performance & Material Architecture

• Class A Volumetric Accuracy: Fabricated to strict metrological tolerances ($\pm 0.03\text{ mL}$). The narrow neck design ensures that minimal shifts in fluid volume result in a pronounced meniscus level adjustment against the permanent graduation mark, maximizing pipetting accuracy.
• Type I Class A Borosilicate Chemistry: Constructed from premium low-expansion borosilicate glass (typically 33 expansion or equivalent). This matrix yields exceptional mechanical strength, a low coefficient of thermal expansion, and near-absolute inertness against aggressive acids, organic solvents, and alkaline wash sequences.
• Ground Glass No. 9 Interlocking Joint: The mouth features a precision-ground, frosted internal taper that matches a No. 9 standard stopper. This tight glass-to-glass or polymer-to-glass interface provides a hermetic seal that prevents vapor leakage or sample evaporation during vigorous inversion mixing.
• High-Contrast Graduation & Serialization: Every flask features a sharp, permanent enamel graduation line fired into the glass barrel. Units are labeled with Class A markings, working temperature limits, and regulatory specifications for direct traceability during laboratory data audits.

Product Specifications

• Catalog Identity / Mix: Assorted Manufacturer Stock (PYREX® 5640-25, KIMAX® 28014-25, VWR® 89090-674, or exact dimensional equivalents)
• Volumetric Capacity: 25 mL Calibration Line
• Accuracy Classification: Class A Metrology Standards (Calibrated "To Contain" / TC at 20°C)
• Volumetric Tolerance: $\pm 0.03\text{ mL}$ strict variance margin
• Joint & Stopper Scale: Standard Taper ($TS$) No. 9 Interlocking Neck
• Material Profile: Clear Type I, Class A Borosilicate Glass | High-Durability Flat Bottom Profile
• Stopper Presentation: Included (Assorted matching Pennyhead Glass, Solid Glass, or Polyethylene No. 9 Stopper elements)
• Packaging Configuration: Sold individually or in assorted laboratory prep packs (Cleaned, inspected, and securely wrapped for damage-free transit)

Key Benefits & Applications

• Analytical Standard Preparation: The standard choice for compounding low-volume calibration standards, stock solutions, and mobile phases for high-performance liquid chromatography (HPLC) or gas chromatography (GC) workflows.
• Quantitative Serial Dilutions: Provides the high volumetric accuracy required to dilute concentrated analytes without introducing cumulative geometric volumetric errors into clinical or industrial diagnostic essays.
• Corrosive Chemical Staging: The inert borosilicate surface handles aggressive acids and organic reagents (like chloroform or methanol) without leaching ions, preventing sample contamination.
• **Economical Laboratory Provisioning:** Ideal for university teaching laboratories, testing facilities, and startup R&D labs seeking premium, certified Class A volumetric glassware at a lower cost than single-brand boxed wholesale lines.

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