At what temperature will steel start to lose its strength and elongate, causing a support beam to collapse?

Steel begins to lose its strength at elevated temperatures, typically starting around 1000°F. At this temperature, the material's yield strength is significantly reduced, which can lead to deformation and elongation. As temperatures increase, the integrity of the steel continues to decline, progressing towards collapse.

While steel can withstand much higher temperatures in its solid state, the critical point for structural integrity is around 1000°F, where it will start to lose its ability to support weight effectively. Understanding this temperature is vital for emergency response strategies, as it guides firefighters in assessing the safety of structures during and after a fire. Higher temperatures can accelerate these effects, but 1000°F is generally recognized as the threshold where strength loss begins to become a critical factor leading to potential collapse.