Is the factor of safety a ratio between the ultimate strength of a material and its safe working stress?

The concept of the factor of safety is fundamental in engineering, particularly in the context of materials and structural design. It serves as a measure of the reliability of a component or structure under expected loads. The factor of safety is indeed defined as the ratio of the ultimate strength of a material (the maximum stress that the material can withstand before failure) to its safe working stress (the maximum stress expected in service that the material can safely handle without risk of failure).

By using this ratio, engineers can ensure that structures or components can withstand unexpected loads or conditions that exceed normal operating conditions. This provides a buffer for safety and helps to mitigate potential failures that could lead to catastrophic events or structural collapse.

Therefore, stating that the factor of safety is a ratio between the ultimate strength of a material and its safe working stress is accurate and reflects a crucial principle in design and material selection. This understanding is vital for any engineer to ensure that products and structures maintain structural integrity throughout their intended lifespan.