Scope:

ASTM A833 is an empirical, dynamic indentation hardness test method that can be used to determine the attributes of metallic materials such as tensile strength and wear resistance. The ASTM A833 test method is primarily used to test items that are too large or bulky to be tested in conventional testing machines. Calibration of comparative test bars can be used to determine hardness numbers for comparison.

Test Procedure:

For ASTM A833 test, a comparative test bar is assembled into the apparatus maintaining a minimum distance of 12.5 mm of the indentation diameter from the edges of the part. The apparatus is equipped with a presetting bar. During the ASTM A833 testing, the apparatus is placed on the surface of the component to be tested with an impact load of approximately 2 kg hammer. The short blow is applied in order to avoid rebound, and thus, a double blow for damaging sharp edges of the ball impression. Hardness of part is determined by using both (test bar and part) impression diameter by employing a calibration device.

 Specimen size:

The diameter of the impression ball shall be 10 ± 0.01 mm according to ASTM A833. The ball shall be made from steel hardened within the range of 60 to 67 HRC. 

Data:

The value of indentation hardness for ASTM A833 testing is reported in SI units and is considered as standard.

Both the diameters of each impression at right angles to each other need to be measured to within 0.05 mm, and their mean value is used as the basis for subsequent result calculation.

Conclusion :

ASTM A833 is an empirical, dynamic indentation hardness test method that can be used to determine the attributes of metallic materials such as tensile strength and wear resistance.