Hardness Test

Introduction
There are three general types of hardness measurements
1) Scratch hardness
• The ability of material to scratch on one another
• Important to mineralogists, using Mohs’scale 1= talc, 10 = diamond
• Not suited for metal � annealed copper = 3, martensite = 7.
2) Indentation hardness
• Major important engineering interest for metals.
• Different types : Brinell, Meyer, Vickers, Rockwell
hardness tests.
3) Rebound or dynamic hardness
• The indentor is dropped onto the metal surface and the
hardness is expressed as the energy of impact.
Suranaree University of Technology May-Aug 2007
Tapany Udomphol