Rockwell and Brinell Hardness of Metallic Materials ASTM E110
ASTM E110 test method covers determination of the indentation hardness of metallic materials by means of portable hardness testers. Portable hardness testers are used for testing articles that are too large or unwieldy to be tested in the usual types of testing machines; for example, to test parts of fixed structures.
The test method for Rockwell and Brinell Hardness of metallic materials by means of portable hardness testers ASTM E110 determines the indentation hardness of metallic materials. ASTM E110 test method defines the requirements for portable instruments that are intended to be used to measure the Rockwell or Brinell hardness of metallic materials by performing indentation tests on the surface of materials in the field or outside of a test lab.
According to ASTM E110, The Rockwell hardness tester utilizes either a steel ball or a conical diamond known as a brale and indicates hardness by determining the depth of penetration of the indenter under a known load. This depth is relative to the position under a minor initial load; the corresponding hardness number is indicated on a dial. Brinell hardness is determined by forcing a hardened steel or carbide ball of known diameter under a known load into a surface and measuring the diameter of the indentation with a microscope. The Brinell hardness number is obtained by dividing the load in kilograms, by the spherical area of the indentation in square millimeters.
The surface of the specimen to be tested must be plane-parallel, level, metallically bare and smooth.
For the Rockwell Hardness test, the minor load is 10 Kgf and major load is 150 Kgf.
For Brinell hardness test, the load is relatively higher i.e. usually between 187.5 and 3000 Kgf, for a 2.5 or 10 mm diameter tungsten carbide ball.