MATERIALS.IE

Description

The Rockwell and Superficial Rockwell hardness test uses either a 120° diamond cone with a 0.2mm radius spherical tip or a ball indenter of a specified diameter. The indentor is pressed into the surface of the test piece using a two step application - a preliminary force P followed by an additional test force. The preliminary force should be applied and maintained for a duration that shall not exceed 3 s. The increase in force from the preliminary force condition to the total test force F should occur in between 1 and 8 s. This force is then maintained for a duration of 4 ± 2 s. The additional force is then removed and, while the preliminary force is maintained, the reading is made after a short stabilisation time. The result of the test is read directly from the machine as:

HR = E - e

where:
E = indenter constant, and
e = the permanent increase in penetration depth

Standards

BS EN ISO 2039-1:2003, (BS 2782-3:Method 365D:1997)	Plastics. Determination of hardness. Ball indentation method
BS EN ISO 2039-2:2000	Determination of Rockwell hardness.
BS EN ISO 6508-1:2016, BS 891:Part 1:1962	Metallic materials. Rockwell hardness test. Test method (scales A, B, C, D, E, F, G, H, K, N, T)
ASTM D785-08	Standard Test Method for Rockwell Hardness of Plastics and Electrical Insulating Materials
(ASTM E1842-96)	Standard Test Method for Macro-Rockwell Hardness Testing of Metallic Materials
ASTM E18-18	Standard Test Methods for Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials