ASTM C338 Glass Softening Point Testing Services

ASTM C338-93 is a test method that measures the ‘flow points’ or temperature at which the viscosity of glass reaches 105 poise. It uses a flow point apparatus to estimate the softening points accurately. The information is helpful in the development and research of glass.

    Talk to an Expert
    ASTM C338 Glass Softening Point Testing Services

    TRUSTED BY

    Precision-driven testing for dimensional accuracy and compliance

    • Overview
    • Scope, Applications, and Benefits
    • Test Process
    • Specifications
    • Instrumentation
    • Results and Deliverables

    Overview

    ASTM C338-93 defines a test method for determining the softening point of glass, which is the temperature at which the glass begins to deform under its own weight. This property is critical for understanding the thermal behavior and forming characteristics of glass materials.

    This test is widely used in glass manufacturing, optics, and materials research. It helps evaluate thermal stability, processing temperatures, and the suitability of glass for high-temperature applications.

    Scope, Applications, and Benefits

    Scope

    ASTM C338 evaluates the softening temperature of glass by observing deformation under controlled heating conditions. The test provides insight into thermal performance and viscosity-related behavior.

    The test evaluates:

    • Softening temperature of glass materials
    • Thermal deformation characteristics
    • Viscosity-related behavior at elevated temperatures
    • Suitability for forming and processing
    • Thermal stability of glass compositions

    Applications

    • Glass manufacturing and processing
    • Optical and specialty glass materials
    • Electronic and display glass
    • Laboratory and scientific glassware
    • High-temperature glass components
    • Research and material development

    Benefits

    • Provides an accurate determination of softening temperature
    • Supports glass processing and forming operations
    • Helps in selecting materials for thermal applications
    • Assists in quality control and product consistency
    • Enables comparison of different glass compositions

    Test Process

    Sample Preparation

    Glass specimens are prepared in specified dimensions and cleaned.

    1

    Heating Setup

    Samples are placed in a furnace with controlled heating rate.

    2

    Temperature Increase

    Temperature is gradually increased until the glass begins to deform.

    3

    Data Recording & Evaluation

    The softening point temperature is recorded based on deformation criteria.

    4

    Technical Specifications

    ParameterDetails
    Applicable MaterialsSoda-lime, borosilicate, and specialty glass
    Temperature Range~500°C to 900°C
    Heating Rate~5°C/min to 10°C/min
    Specimen Size~5 mm to 10 mm diameter
    Measurement MethodDeformation under load/self-weight
    Measured OutputsSoftening point temperature (°C)

    Instrumentation Used for Testing

    • High-temperature furnace
    • Temperature control system
    • Sample holders and fixtures
    • Thermocouples and sensors
    • Optical observation system
    • Data acquisition system

    Results and Deliverables

    • Softening point temperature values
    • Thermal deformation behavior analysis
    • Comparative glass performance evaluation
    • Test condition summary
    • Material suitability assessment
    • ASTM compliance report

    Why Choose Infinita Lab for ASTM C338-93?

    Infinita Lab is a leading provider of ASTM C338-93 and streamlined material testing services, addressing the critical challenges faced by emerging businesses and established enterprises. With access to a vast network of over 2,000+ accredited partner labs across the United States, Infinita Lab ensures rapid, accurate, and cost-effective testing solutions. The company’s unique value proposition includes comprehensive project management, confidentiality assurance, and seamless communication through a Single Point of Contact (SPOC) model. By eliminating inefficiencies in traditional material testing workflows, Infinita Lab accelerates research and development (R&D) processes.

    Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090  to learn more about our services and how we can support you. Request a Quote

     

    Frequently Asked Questions

    ASTM C338-93 includes heating rate, specimen dimensions, temperature measurement, deformation observation, and furnace conditions, determining softening point of glass by identifying temperature at which material begins to deform under specified conditions.

    ASTM C338-93 determines the softening point temperature, indicating when glass transitions from rigid to deformable state.

    ASTM C338-93 is commonly applied to various glass types including soda-lime glass, borosilicate glass, and specialty glasses used in industrial and scientific applications.

    ASTM C338-93 requires a controlled furnace, temperature measurement system, and apparatus to observe deformation of glass specimens during heating.

    ASTM C338-93 evaluates softening under controlled conditions and may not fully represent glass behavior under different heating rates, mechanical loads, or environmental conditions affecting performance in practical applications.

     Request a Quote

    Request a Quote

    Submit your material details and receive testing procedures, pricing, and turnaround time within 24 hours.



    • ddd
      Quick Turnaround and Hasslefree process
    • ddd
      Confidentiality Guarantee
    • ddd
      Free, No-obligation Consultation
    • ddd
      100% Customer Satisfaction
    Home / services / ASTM C338 Glass Softening Point Testing Services

    Discover more from Infinita Lab

    Subscribe now to keep reading and get access to the full archive.

    Continue reading

    ×

    Talk to an Expert

      Connect Instantly

      (888) 878-3090
      Ensure Quality with the Widest Network of Accredited Labs
      • ddd
        Quick Turnaround and Hasslefree process
      • ddd
        Confidentiality Guarantee
      • ddd
        Free, No-obligation Consultation
      • ddd
        100% Customer Satisfaction

        ddd

        Start Material Testing