One if the mechanical properties that may be important to consider is hardness which is a measure of material’s resistance to localized plastic deformation. There are several different tests to measure hardness, including Mohs, Vickers, Knoop, Scleroscope, Brinell, and Rockwell. The Vickers test uses a diamond indenter and measurements are independent of indenter size, while the Knoop test is used for brittle materials where only a small indentation can be made. The Scleroscope test measures rebound hardness using a dropped diamond-tipped hammer, and the Brinell test uses a steel ball indenter under a standard load and time. The Rockwell test indentation hardness that uses different loads or

1. HARDNESS TEST

2. HARDNESS
One if the mechanical properties that may be important to
consider is hardness which is a measure of material’s
resistance to localized plastic deformation.
• Moha( Minerals)
• Vikers
• Knoop
• Scleroscope
• Brinell
• Rockwell

3. MOHA
• Moha is based, the scale on ten minerals that are all readily
available.
• The hardest of material is measured against the scale by
finding the hardest material that the given material can
scratch, and / or the softest material that can scratch the
given material

6. VICKERS HARDNESS TEST
• Vickers Hardness is an alternative to the Brinell method to measure
the hardness of materials.
• The Vickers test is often easier to use than other hardness tests since
the required calculations are independent of the size of the indenter,
and the indenter can be used for all materials irrespective of
hardness.

7. KNOOP HARDNESS TEST
• The Knoop hardness test is a micro hardness test - a test for
mechanical hardness used particularly for very brittle materials or
thin sheets, where only a small indentation may be made for testing
purposes.
• A Diamond indenter point is pressed into the polished surface of the
test material with a known force

8. SCLEROSCOPE HARDNESS
• A scleroscope is a device used to measure rebound hardness . It
consists of a diamond-tipped hammer dropped from a fixed height.

9. BRINELL SCALE
• The Brinell scale characterizes the indentation Hardness of materials
through the scale of penetration of an indenter, loaded on a material
test-piece. It is one of several definitions of hardness in material
science.
• The typical test uses a 10 millimetres (0.39 in) diameter steel ball as an indenter
• Standard Load: 500Kg, 1500Kg, 3000 Kg
• Time: 15 sec. Ferrous metal, 30 sec. Non Ferrous , 120 sec. Magnesium

11. ROCKWELL SCALE
• The Rockwell scale is a hardness scale based on the indentation
hardness of a material.
• There are different scales, denoted by a single letter, that use
different loads or indenters.

13. HR = E - e
F0 = preliminary minor load in kgf
F1 = additional major load in kgf
F = total load in kgf
e = permanent increase in depth of penetration due to major load F1 measured in units of 0.002
mm
E = a constant depending on form of indenter: 100 units for diamond indenter, 130 units for
steel ball indenter
HR = Rockwell hardness number
D = diameter of steel ball