Which of the following is NOT a common property of metals used in mechanical design?

The choice of low electrical conductivity as not being a common property of metals used in mechanical design is accurate because most metals are characterized by their high electrical conductivity. Metals such as copper, aluminum, and silver are commonly recognized for their ability to conduct electricity efficiently, making them essential in a variety of applications, including electrical wiring and components.

In mechanical design, high strength is a desirable property, as it ensures that materials can withstand applied forces without deforming or breaking. Excellent ductility allows metals to be shaped and formed into various structures without fracturing, which is crucial in manufacturing processes. Additionally, good thermal conductivity helps in dissipating heat in applications where temperature management is critical. Therefore, the identified option stands out as not fitting the typical profile of metallic properties relevant in mechanical design.