IS 1161 YST 210, 240 AND 310

IS 1161 is the established Indian Standard for Steel Tubes for Structural Purposes. This standard covers hot-finished seamless and welded (ERW/HFIW) steel tubes used in load-bearing applications. The "YST" designation refers to the Yield Strength of the Tube, with the numerical value representing the minimum yield stress in megapascals ($MPa$).

Grade Analysis

• YST 210: This is the base structural grade, offering a minimum yield strength of $210\text{ MPa}$. It is highly ductile and easy to manipulate, making it ideal for lighter frameworks, handrails, and general fabrication where extreme load-bearing is not the primary concern.

• YST 240: A mid-range grade with a minimum yield strength of $240\text{ MPa}$. It provides a balanced ratio of strength to weight and is the most common choice for industrial sheds, scaffolding, and commercial building supports.

• YST 310: The high-strength variant with a minimum yield strength of $310\text{ MPa}$. It is designed for heavy-duty structural engineering, such as large-span roof trusses, transmission towers, and space frames, allowing for thinner-walled tubes without compromising structural integrity.