ASTM C730 Standard Test for Knoop Indentation Hardness of Glass

ASTM C730 is used to determine the Knoop indentation hardness of glass and to verify the Knoop hardness testing machine by using standard glasses. The Knoop indentation hardness test can be used to test a wide variety of glasses, from television faceplates to polished plate glass. The values are stated in SI units.... Read More

  • Average 30% Cost
    Savings

  • 100% Confidentiality
    Guarantee

  • Free, No-obligation
    Consultation

  • 100% Customer
    Satisfaction

    TRUSTED BY ENGINEERS FROM

    Scope:

    In ASTM C730, the Knoop Indentation Hardness Test is used to determine the Knoop Indentation Hardness of glass. It determines the mechanical hardness of very brittle materials or thin sheets, where only a small indentation may be made for testing purposes. The test is valid for a wide range of test forces and very few samples are required. 

    Test Procedure:

    In ASTM C730, a pyramidal diamond point is pressed into the polished surface of the test sample with a known load, usually 100g, for a specified dwell time, and the dimension of the resulting indentation is measured using a microscope. 

    The indenter leaves a tiny four-sided impression of about 0.01 to 0.1 mm in size. The length of the impression is approximately seven times the width, and the depth is 1/30 the length. Hence, after measuring only the length of the longest side, the area of the indentation can be calculated. The area of the indentation and the weight of the load are then used to calculate Knoop Indentation Hardness. 

    The Knoop indentation hardness test is used in ASTM C720 to test a wide variety of glasses, from television faceplates to polished plate glass. In general, the accuracy of the test will depend on the smoothness of the surface. 

     Specimen size:

    For ASTM C730, the surface of the sample should be smooth and polished. The sample should be over ten times as thick as the indentation depth but not so thick as to affect the hardness of the glass. In general, if specimens are at least 0.10 mm thick, the hardness will not be affected by variations in the thickness. 

    Data:

    For ASTM C730:

    1. Knoop Indentation Hardness (HK) is calculated by

    HK = 14.229(F/D2)

    Where,
    F = the applied load
    D2 = the area of the indentation

    2. The Knoop hardness number (KHN) is calculated by:

    KHN =  (P/A)

    Where,
    P = load
    A = projected area of the indentation

    Conclusion:

    ASTM C730 is used to determine the Knoop indentation hardness of glass and to verify the Knoop hardness testing machine by using standard glasses.

    OUR SERVICES

    Core Materials Testing Services

    Metrology

    A variety of microscopy and spectroscopy tools available for precise measurements from the nano to the meter scale.

    Metrology Testing Services POPULAR TESTS:

    TEM SIMS Profilometry

    Materials Testing

    ASTM and ISO standard and custom chemical, mechanical, thermal, corrosion tests, etc. for all materials metals, ceramic or polymers.

    Materials Testing Services POPULAR TESTS:

    Nondestructive Testing Electrical Testing Chemistry Analysis

    Product Testing

    Thousands of tests for product quality and reliability under heat, humidity, temperature shock, vibration, drop, electrostatic discharge.

    Product Testing Services POPULAR TESTS:

    Vibration Testing Humidity Testing Accelerated Aging

    Looking for Material Testing?

    We have already delivered 10000+ Material Test results to top companies

      Send us a request

        Process for testing
        •  
          STEP 01

          You share material and testing requirements with us

        •  
          STEP 02

          You ship your sample to us or arrange for us to pick it up.

        •  
          STEP 03

          We deliver the test report to your email.

          Let’s work together!

          Share your testing requirements with us and we will be happy to assist you.

          ddd Just share your testing requirements and leave the rest on us!
          • Free, no-obligation consultation
          • Guaranteed confidentiality
          • Quick turnaround time
          • Hassle-free process

            ddd

            Let us combine our capabilities to achieve success!!

              idea icon
              Want to connect with an expert before you leave?