Brinell Hardness Testing Method

what is hardness ?
Hardening Measurement Method
Brinell hardening Test with fig , description, procedure & formula

1. HARDNESS TESTING METHOD
- Hardness is the ability of material to withstand scratching, wear & abrasion
or penetration by harder body.
- The Metals Handbook defines Hardness as “Resistance of metal to plastic
deformation, usually by indentation” It is the property of solid bodies,
where the resistance is offered to plastic deformation and fracture, when
two bodies in contact over small area are pressed together.

HARDNESS MEASUREMENT

Since the definitions of metallurgic ultimate strength & hardness are rather
similar, it can generally be assumed that strong metal is also a hard metal.
Hardness measures, the metal's resistance to the penetration of a non-
deformable ball or cone. The tests determine the depth, which such a ball or
cone will sink into the metal, under a given load, within a specific period of
time. The followings are the most common hardness test methods used in
today’s technology:

(1) Rockwell hardness test (5) Knoop hardness
(2) Brinell hardness (6) Shore
(3) Vickers (7) Mohs Hardness
(4)Barcol Hardness

Brinell Hardness
The Rockwell Hardness test is a hardness measurement based on the net
increase in depth of impression as a load is applied. Hardness numbers have no
units & are commonly given in the R, L, M, E and K scales. The higher the number in
each of the scales means the harder the material..
- The Brinell hardness tester uses a hardened spherical ball, which is forced
into the surface of the metal. This ball is 10 mm (0.3937 inch) in diameter.
- The pressure of 3,000 kg is used for ferrous metals & 500 kg for nonferrous
metals. The pressure must be maintained at least 10 seconds for ferrous
metals and at least 30 seconds for nonferrous metals.
• The load is applied by hydraulic pressure, by means of hand pump or an
electric motor, The Pressure gauge indicates the amount of pressure. There
is release mechanism for relieving the pressure after the test has been
made, & calibrated microscope is for measuring the diameter of the im-
pression in mm.
- To determine the Brinell hardness number for a metal, measure the diameter of the im-
pression, using the calibrated microscope furnished with the tester. Then convert the
measurement into the Brinell hardness number on the conversion table furnished with
the tester.
- The Brinell Hardness Number (BHN) which is the pressure per unit force area of indenta-
tion in kg per square meter, is calculated by









356 BHN, where 356 is the calculated hardness W in-
dicates that carbide ball was used.

Brinell Hardness test is best for measuring hardness
of Grey C.I. casting consisting of soft flake graphite,
iron & hard iron carbide.
The main drawback of the Brinell test is the need to
optically measure the indent size. This requires that
the test point be finished well enough to make an ac-
curate measurement

Prepared by,
(1) PATEL SHREY B (170953119031)
(2) RATHVA YOGESH (170953119035)
(3) SINDHA KISHAN (170953119045)
(4) DIVYESH RATHOD (170953119036)
(5) PANDYA ABHISHEK (170953119022)
Guided by,
SUSHIL CHAURAISA
MSM - 2131904 B.E. MECH, Sem - III, 2017
(MECH DEPTT.)