Chemglass Hollow Pennyhead Glass Stopper 24/40 Lot of 4 Stoppers

Chemglass Hollow Glass Pennyhead Stopper – 24/40 Standard Taper Joint, Borosilicate Glass, Autoclavable (MPN: CG-3000-05)

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The Chemglass CG-3000-05 is a premium, laboratory-grade ground glass stopper engineered to provide an airtight, leak-proof mechanical seal for scientific glassware assemblies. Precision-ground from high-purity, low-extractable borosilicate glass, this stopper features an industry-standard 24/40 Standard Taper joint size. The specialized hollow body construction features a closed-bottom design that prevents chemical vapors from collecting inside the upper cavity, while significantly reducing the component's total weight to minimize physical stress on delicate flask necks. Outfitted with an ergonomic, flat pennyhead style handle, this autoclave-safe stopper allows for secure, non-slip manipulation during distillation, organic synthesis, and chemical storage workflows.

Technical Performance and Design

• Precision Ground 24/40 Joint: Meticulously ground to exact Standard Taper dimensional tolerances, establishing a highly uniform, flush fitment inside any female 24/40 outer joint without slipping or leaking.

• Hollow Closed-Bottom Architecture: The inner chamber is hollowed out to save weight, but sealed off completely at the bottom base. This blocks volatile solvent vapors or condensation from entering the upper head, making clean-up fast and straightforward.

• Heavy-Duty Borosilicate Glass: Fabricated from premium borosilicate glass characterized by a low coefficient of thermal expansion. This material delivers outstanding thermal shock resistance and broad chemical compatibility with strong acids, bases, and aggressive organic solvents.

• Ergonomic Flat Pennyhead Handle: Designed with an extended, vertical flat disk top that provides excellent leverage. This profile gives lab technicians a secure, natural finger grip when inserting or freeing frozen ground joints, even while wearing heavy safety gloves.

Product Specifications

• Catalog Number / MPN: CG-3000-05 (Cross-listed as CG300005 / 80071-926)

• Manufacturer / Brand: Chemglass Life Sciences

• Standard Taper Joint Size: 24/40

• Stopper Silhouette Profile: Hollow Pennyhead Style with Closed Base

• Material Composition: Premium Laboratory Borosilicate Glass

• Sterilization Compatibility: Fully Steam Autoclave Safe

• Packaging Configuration: Sold individually (Each)

Key Benefits and Applications

• Boiling and Recovery Flask Sealing: The primary glass closure choice for sealing active round-bottom flasks, recovery vessels, and mixing cylinders engaged in rotary evaporation or fractional distillation setups.

• Air-Sensitive Chemical Archiving: When paired with a light layer of hydrocarbon or silicone joint grease, it forms an exceptionally tight physical moisture barrier to preserve volatile stocks or moisture-sensitive reagents.

• Bypassed Weight Stress: The hollow engineering drastically cuts down top-heavy weight strain on horizontal glassware joints, protecting expensive multi-neck distillation manifolds from structural snapping or torque fractures.

• High-Temperature Adaptability: Built to maintain physical sealing properties across massive thermal operational boundaries, remaining perfectly safe for high-temperature chemical reactions and high-heat sterilization washes.

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