4″ x 4″ x 3/8″ (.375″ wall) square steel tubing is manufactured from ASTM A500 steel, a cold-formed carbon steel specification designed for extreme-duty structural applications. This hollow structural section (HSS) features a large square profile with an extra-thick wall, delivering maximum strength, rigidity, and durability for the most demanding industrial and construction projects. Typically produced in Grade B, it provides excellent weldability, precise dimensional consistency, and reliable performance under high stress and heavy loads.

Applications:
4″ square steel tubing (3/8″ wall) is commonly used in:
• Heavy structural columns, beams, and support frames
• Industrial machinery bases and heavy equipment supports
• Bridges, platforms, and large-scale construction projects
• Trailer frames and heavy-duty automotive fabrication
• Security structures and reinforced barriers
• Load-bearing and high-stress structural assemblies

Advantages:
• Extreme strength: Extra-thick wall (.375″) supports very high loads and resists deformation
• Superior durability: Designed for the most demanding structural applications
• Excellent weldability: Compatible with MIG, TIG, and stick welding
• High rigidity: Minimizes flex and deflection under stress
• Consistent quality: Manufactured for precise dimensions and reliable performance

Summary:
The 4″ x 4″ x 3/8″ ASTM A500 square steel tube is an ultra heavy-duty structural material built for maximum strength and durability. Its extra-thick wall and robust design make it ideal for high-load, high-stress applications in industrial, commercial, and large-scale construction projects.