At what strain is yield strength typically determined?

Yield strength is typically determined at a strain of 0.2%. This convention is widely accepted in materials science and engineering, particularly for metallic materials. The yield strength represents the stress at which a material begins to deform plastically, meaning that the deformation is permanent and non-recoverable.

Defining yield strength at 0.2% strain allows for a consistent measurement across different materials and helps to avoid ambiguity that can arise from using a nominal elastic limit. This 0.2% offset method is especially useful because it provides a clear demarcation between elastic and plastic deformation, ensuring that engineers and designers can make reliable predictions about how a material will behave under load.

Using a consistent strain percentage like 0.2% enables a standardized approach that is critical for applying material performance in real-world applications. Thus, this practice aligns with industry standards and benchmarks, making it the most practical choice in determining yield strength.