A cylindrical metal specimen 12.7 mm (0.5 in.)
in diameter and 250 mm (10 in.) long is to be
subjected to a tensile stress of 28 MPa (4000
psi); at this stress level the resulting deformation
will be totally elastic.

If, in addition, the maximum permissible diameter
decrease is 1.2 103 mm (4.7 105 in.)
when the tensile stress of 28 MPa is applied,
which of the metals that satisfy the criterion in
part (a) are suitable candidates? Why?

*( part a was : If the elongation must be less than 0.080
mm (3.2 103 in.), which of the metals in
Table 6.1 are suitable candidates? Why? )