Properties of Metals
We can now see that Young's Modulus may be easily calculated, provided that the stress and
corresponding unit elongation or strain have been determined by a tensile test as described
previously. Strain (e) is a number representing a ratio of two lengths; therefore, we can
conclude that the Young's Modulus is measured in the same units as stress (s), that is, in pounds
per square inch. Table 1 gives average values of the Modulus E for several metals used in DOE
facilities construction. Yield strength and ultimate strength will be discussed in more detail in
the next chapter.
Yield Strength (psi)
Ultimate Strength (psi)
1.0 x 107
3.5 x 104 to 4.5 x 104
5.4 x 104 to 6.5 x 104
2.9 x 107
4.0 x 104 to 5.0 x 104
7.8 x 104 to 10 x 104
3.0 x 107
3.0 x 104 to 4.0 x 104
5.5 x 104 to 6.5 x 104
What is the elongation of 200 in. of aluminum wire with a 0.01 square in. area if it
supports a weight of 100 lb?
(100 lb) (200 in.)
(0.01 in.2) (1.0 x 107 lb/in.2)
= 0.2 in.