2. Group no:5(CE-39 to CE-50)
Presented By: Nabeel Afzal
& Mirza Abid Hussain

3. Subjects of Interest
Objectives
Introduction
Brinell hardness test
Vickers hardness test
Rockwell hardness test

4. Objectives
To check hardness of sample
To check quality of sample in
industry.
It gives indirect measure of
strength of material.

5. Introduction
Definition:
“Hardness is a resistance
to deformation”.
In mechanics of materials “hardness
is more likely to mean the resistance to
indentation”. Larger
Impression
Softer
Materials

6. Introduction
There are three general types of hardness
measurements:
1. Scratch hardness
2. Indentation hardness
3. Dynamic hardness
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 copper = 3, martensite = 7.

7. Introduction
Indentation hardness:
Hardness of a material to resist indentation
is called indentation hardness.
 Different types:
Brinell, Vickers,
Rockwell hardness tests.
Rebound or dynamic hardness:
 The indenter is dropped onto the metal
surface and the hardness is expressed as the
energy of impact.

8. Brinell Hardness Test(ASTM E10)
Introduction:
Swedish Engineer Johan August Brinell introduced the first
standardized indentation-hardness test in 1900. The
Brinell hardness test consists in indenting the metal surface
with a 10-mm(0.39in) diameter steel ball at a load range of
500-3000 kg, depending of hardness of particular
materials.
For softer materials, a smaller force is used; substituted for
the steel ball. For harder materials, larger force is used,
a tungsten carbide ball is substituted.

9. Brinell Hardness Test
APPARATUS
 Brinell Hardness testing
Machine
 Steel ball indenters
 Steel sample

10. Procedure:
Firstly required indenter is fixed in the machine and
take the machine table to the suitable height and
focus the sample place the sample in the machine
load is applied on the sample indentation is
produced load is noted from the machine and Dia of
the indentation is measured .

11. The indentation is measured and hardness calculated as:
BHN= 2P
3.14D (D- √D² - d²)
where:
P = applied force (kgf)
D = diameter of indenter (mm)
d = diameter of indentation (mm)
Brinell hardness is sometimes quoted in megapascals , the Brinell
hardness number is multiplied by the acceleration due to gravity,
9.80665 m/s2, to convert it to megapascals. The BHN can be
converted into the ultimate tensile strength (UTS). The relationship
is based on Meyer's index (n) from Meyer's law. If Meyer's index is
less than 2.2 then the ratio of UTS to BHN is 0.36. If Meyer's
index is greater than 2.2, then the ratio increases.

12. BHN is designated by the most commonly used test
standards (ASTM E10-14 and ISO 6506–1:2005)
as HBW (H from hardness, B from brinell and W from
the material of the indenter, tungsten (wolfram)
carbide). In former standards HB or HBS were used to
refer to measurements made with steel indenters.
HBW is calculated in both standards using the SI units
as
HBW=0.102 2P
3.14D(D-√D² -d²)
where:
P = applied force (N)
D = diameter of indenter (mm)
d = diameter of indentation (mm)

13. Sr.No. Specimen Ball Dia.(mm) Dia of indentation(d) mm Mean
Diad(mm)
Load
(Kg)
B.H.N
d1 d2 d3
1 Copper 10 4.15 4.16 4.17 4.16 500 35
2 Aluminum 10 6.15 6.16 6.17 6.16 500 15
3 Mild steel 10 2.28 2.27 2.29 2.28 500 120
OBSERVATIONS AND CALCULATIONS:
METHOD OF REPORTING HARDNESS:
For example
75 HB 10/500/30
Where
75 = hardness value
H = Hardness
B =Brinell
10 = Diameter
500 = Force
30 = Time

15. “Vickers hardness test”
Introduction:
The Vickers hardness test was developed in 1921 by Robert
L. Smith and George E. Sandland at Vickers Ltd as an
alternative to the Brinell method to measure the hardness of
materials.
Vickers hardness test uses the loads ranging from 1-
120 kgf, applied for between 10 and 15 seconds.

16. Significance:
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. The basic
principle, as with all common measures of hardness, is to observe the
questioned material's ability to resist plastic deformation from a standard
source. The Vickers test can be used for all metals and has one of the
widest scales among hardness tests

17. Apparatus:
vicker hardness testing machine.
steel specimen.
pyramid diamond indenter of vicker.

18. Procedure:
When specimen is placed in vicker
machine and after applying load it produce indentation in the
given specimen the load is note from the scale. Diagonals lengths
of indentation are measured, and angle between the diamond
faces . From the values known after the vicker hardness test .
Vicker hardness number can computed.

19. Observations and Calculations:
The Vickers hardness number (VHN)is defined as the load
divided by the surface area of the indentation.
VHN= 2Psin(θ/2) = 1.854P
L² L²
Where
P = is the applied load in kgf ,
L = is the average length of diagonals in mm,
θ = is the angle between opposite faces of diamond (136º)
The unit of hardness given by the test is known as the Vickers Pyramid
Number (HV) or Diamond Pyramid Hardness (DPH).
Sr.no specimens Load
(kg)
Diagonal length
L1 (mm)
Diagonal length
L2 (mm)
Average
Length(mm)
1
2
3

20. Examples of HV values for various materials[6]
Material Value
316L stainless steel 140HV30
347L stainless steel 180HV30
Carbon steel 55–120HV5
Iron 30–80HV5
Martensite 1000HV
Diamond 10000HV

21. Rockwell hardness test
ASTM E18 METAL
ISO 6508 METAL
ASTM D785 PLASTIC
Introduction:
Working in a ball-bearing manufacturing plant in 1919, Stanley P.
Rockwell invented the Rockwell hardness test as a tool for
obtaining a rapid and more accurate measure of the hardness of
ball races .
Significance:
The test is fast, inexpensive, and relatively non-destructive,
leaving only a small indentation in the material. The simplicity in
the operation of a Rockwell hardness machine has provided the
added advantage that Rockwell hardness testing usually does
not require a highly skilled operator .

22. Apparatus:
Rockwell hardness testing machine
specimen for testing
indenters (ball and diamond)

23. Procedure:
In the case of the Rockwell hardness test firstly placed the
sample in machine after setting the machine two levels of force
are applied to the indenter at specified rates and with specified
dwell times, the Rockwell hardness of the material is based on
the difference in the depth of the indenter at two specific times
during the testing cycle, indicated by the X marks in Figure 1.
The value of hardness is calculated using a formula that was
derived to yield a number falling within an arbitrarily defined
range of numbers known as a Rockwell hardness scale

24. Types according to applied
load
Superficial hardness:
Test in which minor load is 3 kgf and the major loads are 15, 30,
or 45 kgf.
Regular hardness:
The minor load is 10kgf and major loads are 60, 100, or 150 kgf.
Rockwell test method are defined in the following standard,

25. Observations and
Calculalations
For scales that use a spheroconical diamond indenter, the Rockwell
hardness number is calculated from h (in mm) as:
Regular Rockwell Hardness = 100 − h
0.002 mm
Rockwell Superficial Hardness
= 100 − h
0.001 mm
Sr. no specimens Minor load
depth
h1 (mm)
Major load
depth
h2 (mm)
Difference
h=h2-h1
(mm)
1
2
3

26. For scales that use a ball indenter, the Rockwell
hardness number is calculated from h (in mm) as:
Regular Rockwell Hardness
= 130 −
h
0.002mm
Rockwell Superficial Hardness
= 100 −
h
0.001mm
h = difference in indentation depths is measured

27. Precautions:
Place the sample carefully on the
machine table.
Fix the indenter properly.
Reading must be note carefully.

28. Thanks