5 6
Relationship between selected test pressure and applied
weights is shown as follow:
Hanger + Weight A + Weight B + Weight C
Hanger + Weight A + Weight B
Hanger + Weight A
Applied Weights
Test Pressure
Graduation, N
588
980
1470
Scale
HRA
HRB
HRC
5
Preparation prior to the use:
Surface of the specimen to be tested must be smooth and
clean, free from dirt, scaling, indentation or significant marks
resulted from machining. Scale, Indenter, Testing Pressure
and Applicable Range for Rockwell Hardness Test .
Operation
1
Minimum thickness of the specimen shall be larger than 10
times the depth of indenture. No obvious deformation shall be
seen on back of the specimen after hardness test.
The specimen to be tested shall be placed in stable state on
top of the test stock. It shall be fixed during the test process.
Ensure that the test pressure is perpendicularly exerted on
the specimen.
In case of a cylindrical shape specimen to be tested, the V
type test stock shall be used and offset needs to be made to
the values. Offset for cylindrical shape specimen shall be a
positive value.
Scale
A
D
C
F
B
G
H
E
K
Indenter
Diamond indenter
conical angle:
120 spherical
radius at vertex:
0.2 mm
°
Ball indenter
diameter:
1.5875mm (1/16in)
Ball indenter
diameter:
3.175mm (1/8in)
Initial
Pressure
(N)
98.07
Combined
Pressure
(N)
588.4
980.7
1471.0
588.4
980.7
1471.0
588.4
980.7
1471.0
Applications
hard alloy, carbide for
surface quenched steel,
hard steel sheet
thin steel sheet, surface
quenched steel
quenched steel, tempered
steel, hard cast iron
cast iron,a luminum,m agnesium
alloy, bearing alloy, annealed
copper alloy, mild steel sheet
mild steel, aluminum alloy,
copper alloy, malleable cast
iron, annealed steel
phosphorus iron, beryllium
bronze, malleable cast iron
aluminum, zinc, lead etc.
bearing alloy, tin, hard plastics,
and other soft materials
The most commonly used scales for Rockwell hardness test are A, B and C.
Hardness tester operation procedure:
2
Plug the power cord and turn on the boat-shape switch. The
illuminating light is on.
Choose a scale according to table based on the rough
hardness of the material to be tested. Rotate the pressure
selecting hand-wheel clockwise to set the total pressure.
When use the diamond indenter, press the head of diamond
with middle finger and gently push it into the hole on indenter
rod till it rests neatly on the supporting surface, then slightly
tighten the indenter locking screw, and place the specimen on
test stock.
Rotate the turn wheel clockwise to let the lifting screw move
upward, ensuring that the specimen to be tested slowly
contact with the indenter with no impact, till the short pointer
on the centigrade panel turn from the first step black point to
