Tensile Strength for Springs
A music wire with a diameter of 7.25 mm will be used as a spring material in a piano. Calculate the minimum tensile strength of the wire.
Hint
For spring materials, the minimum tensile strength for common spring steels can be determined from:
$$$S_{ut}=\frac{A}{d^{m}}$$$
where
$$S_{ut}$$
is the tensile strength in MPa, and
$$d$$
is the wire diameter in millimeters.
Hint 2
$$A$$
and
$$m$$
can be found in the below table:
For spring materials, the minimum tensile strength for common spring steels can be determined from:
$$$S_{ut}=\frac{A}{d^{m}}$$$
where
$$S_{ut}$$
is the tensile strength in MPa,
$$d$$
is the wire diameter in millimeters, and
$$A$$
and
$$m$$
can be found in the below table:
Since the problem is asking for the minimum tensile strength of a music wire:
$$$S_{ut}=\frac{2060}{(7.25mm)^{0.163}}=\frac{2060}{1.381}=1492\: MPa$$$
1492 MPa