S355j2 St52 High Strength Seamless Square Tube for Heavy Load Structure

Seamless square steel tubes in 200x200mm size with wall thickness from 5mm to 20mm are produced for heavy structural applications, ensuring enough load capacity for building columns and frames.

S235JR and S355J2 carbon steel grades offer yield strength of 235 MPa and 355 MPa respectively, giving engineers reliable material options for different load requirements.

Produced by hot rolled seamless process without any welding seam, these square tubes eliminate weld defects and provide uniform strength around the entire section.

For building columns, truss structures, machinery frames and guardrail systems, seamless square tubes deliver clean appearance and stable structural performance.

Every tube is verified by ultrasonic testing and hydrostatic pressure testing before shipment, guaranteeing no internal cracks and no leakage for pressure applications.

Black painted, galvanized or oiled surface treatments protect the tubes from corrosion during storage, transportation and long term outdoor service.

Standard 6-meter length with custom cutting from 1 meter to 12 meters is available, reducing material waste and on-site cutting cost for your project.

A Mill Test Certificate showing chemical composition and mechanical properties accompanies every shipment, fully traceable from steelmaking to delivery.

Delivery within 15-25 days after deposit for standard sizes, with priority scheduling for urgent projects and large quantity orders.

Free cutting service, sample availability and third-party inspection by SGS or BV are all supported to help you confirm quality before mass order.