IN ANSWERING QUESTIONS 2-40 THROUGH 2-42,
REFER TO TABLE 1-4 IN THE TEXTBOOK.
2-40.
You are testing a piece of steel on
the Rockwell tester using the
diamond penetrator and both
weights.
If the reading is 40 on
the black scale and 70 on the red
scale, what is the hardness number?
C-40
2.
C-70
3.
D-40
4.
D-70
2-41.
When the Rockwell hardness tester
is being used, the black dial
numbers should be read only when
what scale or penetrator is used?
1.
E scale
2.
F scale
3.
Diamond penetrator
4.
l/16-inch ball penetrator
2-42.
In what way should the pan be
weighed when making a G scale test
on the Rockwell hardness tester?
1.
With the red weight only
2.
With the black weight only
3.
With both the red and black
weights
4.
Without either the red or black
weight
2-43.
When testing a metal of completely
unknown hardness on a Riehle
hardness tester, a preliminary
reading should be taken on what
scale as a guide in selecting the
proper scale to be used?
A
2. B
3. F
4. G
IN ANSWERING QUESTION 2-44, REFER TO TABLE
1-5 IN THE TEXTBOOK.
2-44.
Which of the following aluminum
alloys is the hardest?
2-45.
You check the condition of the
point of the Barcol tester by using
the test disc and find the
indicator reading is NOT within the
specified range.
You should
correct this condition by first
following what procedure?
Grind the point
2.
Install a new point
3.
Adjust the lower plunger guide
4.
Adjust the plunger upper guide
nut
2-46.
When an Ernst hardness tester is
used, a direct reading from which
of the following scales should NOT
be used?
Brinell scales
2.
Rockwell A scale
3.
Rockwell B scale
4.
Rockwell C scale
2-47.
The canopies of most high-speed
naval aircraft are made of what
material?
Stretched acrylic plastic
2.
Laminated acrylic plastic
3.
Laminated thermoplastic
4.
Thermoshield
2-48.
When viewed from its edge, which of
the following plastics is
practically clear?
1.
Heat-resistant acrylic
2.
Craze-resistant acrylic
3.
Thermosetting polyester
4.
Heat-resistant polyester
2-49.
You can distinguish a plastic
enclosure from a glass enclosure by
using which of the following
methods?
1.
Checking for a nonringing sound
while tapping lightly
2.
Checking the ease with which it
is drilled
3.
Checking its reaction to
acetone
4.
Checking its reaction to hexane
1.
3003-0
2.
3003-1/2H
3.
5052-1/2H
4.
6061-T
9
1.
1.
1.
1.
1.
