ASTM C773 Standard Test Method for Compressive Strength of Fired Whiteware Materials

    ASTM C773 Introduction

    ASTM C773 is essential for selecting whiteware materials for manufacturing various products such as dinnerware, sinks, toilets, and dental implants. It ensures quality control by determining the strength of whiteware, aiding in the selection process. The first procedure is suitable for testing whiteware products with low to moderately high strength levels, typically up to 150,000 psi or 1030 MPa. The second procedure, on the other hand, is specifically designed for testing high-strength ceramics, typically exceeding 100,000 psi or 690 MPa.

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    ASTM C773 Test Procedure

    Sample CheckingSamples are initially inspected for flaws, and any with visible cracks are discarded. Dye checking is then performed on the sample’s surface to identify any remaining flaws.
    Immersion in an ultrasonic bathThe sample undergoes cleaning by immersion in a hot, detergent-filled ultrasonic bath. After removal, it is rinsed with hot water, dried, and cooled to room temperature in a desiccator.
    Application of LoadFlawless, cleaned, and dried samples are positioned between the testing machine’s contact blocks. A continuous load is then applied to the sample until it fractures.

    C773 Equipment and Sample Preparation

    Specimen DetailsThis test assesses the potential load-bearing capacity of a ceramic material.
    Specimen SizeThe sample must be cylindrical, either cut from whiteware or manufactured specifically for the test. A minimum of ten such samples should be provided, each smaller than 80% of the capacity of the testing machine.

    C773 Test Results and Interpretation

    The ASTM C773 test calculates the compressive strength of ceramic specimens and whiteware materials in various manufacturing applications, such as dinnerware, sinks, toilets, and dental implants.

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    ASTM C773 is related to tests, including ASTM E4 for verifying the force of testing machines, ASTM E6 for methods of mechanical testing, and ASTM E165 for liquid penetration examination. 

    Use of C773 in Various Industries

    A good number of industries in manufacturing ceramics, sanitary ware, electrical insulators, advanced materials, etc., rely much on this standard when evaluating the mechanical properties of their fired whiteware products toward applications where high compressive strength is needed.

    Materials Commonly Tested with C773

    Tests are performed to check the compression strengths of fired whiteware materials such as porcelain and china for possible applications as electrical insulators, dinnerware, and architectural ceramics.

    Common Challenges and Troubleshooting in C773 Testing

    Even uneven surfaces and poor load distribution cause difficulties in testing, primarily due to problems with sample preparation. Troubleshooting involves appropriate specimen alignment, calibrated equipment, and procedures for preparing specimens before the test.

    Safety and Best Practices in C773 Testing

    Testing safety requires wearing protective gear, calibrating the test machine, use of controlled loading rates, and regular inspection of equipment to prevent hazards such as the failure of specimens by unexpected failure and to keep the test specimens safe.

    Importance of C773

    This specification is critical because it provides reliable data related to the compressive strength of fired whiteware materials to ensure the material does not fail in critical applications or compromise product durability and safety.

    Updated on September 17, 2026

    Divakar Shukla
    About Author
    Divakar Shukla
    Divakar Shukla is an Electrical and Electronics Engineer specializing in the convergence of embedded systems architecture, industrial automation, and applied artificial intelligence.
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