The MEDILAB Hollow Glass Stopper is a precision-crafted, hexagonal flat-bottom stopper made from high-quality Borosilicate Glass 3.3. Designed for use with standard jointed laboratory glassware, it provides an airtight and reliable seal for reagent bottles, flasks, cylinders, and multiple other vessels. Its hollow design ensures reduced weight, excellent handling, and optimal sealing performance across various laboratory and industrial applications.

 Key Features

• Manufactured from premium Borosilicate Glass 3.3 for exceptional durability and clarity
• Hexagonal head for easy grip, secure handling, and safe insertion/removal
• Hollow structure reduces overall weight while maintaining mechanical strength
• Perfectly ground joint ensures airtight sealing and leak-free operation
• Chemically inert surface suitable for acids, alkalis, solvents, and reagents
• Highly resistant to thermal shock, ideal for heating, cooling, and autoclave cycles
• Available with flat-bottom or tip-bottom design as per application needs
• Universally compatible with jointed cylinders, volumetric flasks, reagent bottles, and standard interchangeable glassware

 Material Specifications

• Material: Borosilicate Glass 3.3

Thermal Properties:

• Coefficient of thermal expansion: 3.3 × 10⁻⁶ /°C
• Excellent thermal shock resistance
• Suitable for autoclaving and controlled temperature applications

Chemical Properties:

• High resistance to most chemicals, corrosive vapours, and solvents
• Non-reactive surface ensures sample purity

Mechanical Properties:

• High mechanical strength with long service life
• Precision-ground joints for superior fit and seal

Standards Compliance:

• Conforms to ISO/DIN standards for laboratory glassware interchangeability
• Manufactured as per international laboratory glass specifications (ISO 3585 for borosilicate)

Technical Specifications

• Joint Sizes Available: All standard joint sizes, such as 10/19 to 50/42 (as per the standard size table)

• Design Options:

  • Hexagonal flat-bottom (standard)

  • Tip-bottom version (optional)

• Tolerance Class:

  • Precision-ground; suitable for all standardised ground joints

  • Not intended for volumetric calibration

• Weight: Reduced weight due to hollow construction

• Packaging:

  • Individually wrapped in protective sleeves

  • Export-quality, shock-resistant cartons to prevent breakage during transit

• Accessories Included:

  • Supplied as a stopper only (no additional components required)

Handling & Precautions

• Insert and remove the stopper gently to avoid stress on the ground joint
• Avoid using excessive force when sealing; a properly ground joint creates a natural seal
• Clean with mild laboratory detergents; avoid abrasive pads or strong alkaline cleaners
• Allow gradual heating and cooling to ensure long life and prevent thermal shock
• Check for chips, cracks, or scratches before use and replace if damaged
• Do not use with frozen or crystallised chemicals that may exert pressure on the joint

Applications

• Suitable for reagent bottles, volumetric flasks, distillation setups, and jointed cylinders
• Ideal for academic laboratories, research institutions, and quality control laboratories
• Widely used in pharmaceutical, chemical, biotech, environmental, and analytical laboratories
• Essential for safe storage, sealing, and handling of chemical reagents and solutions
• Supports daily workflow in analytical chemistry, wet labs, sample preparation, and reagent management

 Why Choose MEDILAB

• Over 35 years of expertise in scientific glassware manufacturing
• Trusted by institutions and industries across 40+ countries
• Precision-made from export-quality Borosilicate Glass 3.3
• Stable global supply chain and consistent manufacturing standards
• OEM and private labelling available for distributors and brand owners
• Robust, export-grade packaging ensures safe international delivery
• Recognised for reliability, dimensional accuracy, and long-term performance