Test Methods

The units are usually given in inches per degree Fahrenheit. It is the change in length (inches) of one inch of a part caused by changing the temperature one degree.

The change in length = Original length x the coefficient of expansion x the change in temperature = 10 x .00006 x 40 = .024 inches.

Sometimes a designer knows a part can only bend or deflect a certain amount. If the maximum amount of bending and the shape of the part are known, then the designer can often predict how STIFF a material must be. The measurement of the STIFFNESS of a material is called the "MODULUS" or "MODULUS OF ELASTICITY." The higher the modulus number, the stiffer the material; and conversely, the lower the number, the more flexible the material. The Modulus also changes as the temperature changes