The document outlines the procedure for conducting a Rockwell hardness test to determine the hardness of mild steel. Key steps include using a Rockwell hardness testing machine to apply a load to an indenter pressed against the steel specimen, recording the reading once loading is complete, and taking multiple measurements to calculate an average hardness value in HRB units. Different Rockwell scales like B and C are used because materials require different loads to obtain accurate hardness readings.

1. JJ508
ENGINEERING
LABORATORY 3
MATERIAL TECHNOLOGY
EXPERIMENT 2
ROCKWELL HARDNESS TEST

2. At the end of the lab session students should be able:
To determine the hardness of mild steel using
Rockwell scales.
Experiment Outcomes

3.  Rockwell hardness testing machine.
 Mild steel specimen.
Apparatus/Equipment

4.  Switch on the power switch.
 Set the scale, load and indenter according to LCD display.
 Set the test mode to Rockwell.
 Make sure the indenter, material, and platen are clean.
 Pick a spot for your test at least 3 indenter diameters (HB)
from edges and dents from previous tests.
Procedures

5.  Turn the crank CW to bring the material into contact with
the indenter. Keep turning until buzzer is on.
 Wait until loading light (red) is off. Record the reading on
the display screen.
 Turn the crank CCW to unclamp the test piece.
Procedures

6. Table 1
Result/Data
Specimen Hardness, HRB
Mild Steel
1
2
3
AVERAGE VALUE

7.  Two hardness readings, 75HRB and 85HRB, which one
is harder? Why?
 For Rockwell Hardness Test to test the material
hardness we use different scale, why do we need to
use different scale like Rockwell-B scale and Rockwell-
C scale?
Discussion

8.  Your conclusion should be related to your practical
and theoretical understanding on the related topic.
Conclusion and Recommendation