## 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**

**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**

**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