What is the minimum preheat temperature for steel 1 1/4" thick A572 Gr.60?

The minimum preheat temperature for steel, such as A572 Grade 60, is determined by various factors, including the thickness of the material and the intended welding processes. For materials that are 1 1/4" thick, a preheat temperature of 400°F is recommended to minimize the risk of cold cracking and ensure proper mechanical properties in the welded joint.

This temperature helps to adequately prepare the base metal, reducing thermal gradients during welding and allowing for better fusion between the weld and the base material. Lower preheat temperatures may not provide sufficient heat to adequately mitigate these risks, especially in thicker sections like 1 1/4". Proper preheating is a crucial step in the welding process to ensure the integrity and durability of the welded structure.