Rockwell Hardness
The Wilson Rockwell Model 523 is a microprocessor controlled hardness tester. The displays prompt the operator for the indenter and loads. The tester monitors and controls the loading of the specimen and displays the hardness result on a digital readout.
A penetrator is pressed into a material to determine hardness. The basic premise of the Rockwell test system is that the depth of penetration decreases with increasing hardness. The minor load is applied to condition the surface. The major load is applied and then released. The minor load remains. The difference between depth of penetration before and after application of the major load is used to calculate the Rockwell hardness number.
The test scale scroll key is pressed to select the desired test. The required minor and major loads and indenter are displayed. The minor load conditions the surface and is fixed at 10kg for all tests. The major load is adjusted by the hand wheel of the right side. The specified penetrator is installed into the indenter fixture. A flat anvil or V-shaped anvil is installed to support the specimen.
Rockwell B and Rockwell C are the typical tests in this facility. The Rockwell B penetrator is a 1.59mm (1/16 inch) diameter tungsten-carbide ball and the major load is 100kg. The Rockwell C test is performed with a Brale penetrator (120°diamond cone) and a major load of 150kg.
The specimen is placed on the anvil and raised to apply the minor load by turning the handwheel at the bottom of the anvil column. The minor load indicator extends to the Set position. A brake activates to lock the handwheel and the major load is automatically applied. The word TESTING is displayed. The Rockwell hardness is displayed. The anvil is lowered to remove the specimen.