Q355B (16Mn) high quality seamless steel pipe

Product introduction

Q355B (16Mn) Seamless Steel Pipes

Q355B is a high-strength low-alloy structural steel grade widely used in construction, mechanical engineering, and industrial manufacturing. Formerly known as 16Mn under the GB/T 1591 standard, Q355B offers a reliable combination of strength, toughness, and weldability. Its balanced mechanical properties make it suitable for applications requiring dependable structural performance and good fabrication characteristics.

Chemical Composition: Q355B seamless steel pipes typically contain 0.24% maximum carbon (C), 0.55% maximum silicon (Si), 1.00–1.60% manganese (Mn), 0.035% maximum phosphorus (P), and 0.035% maximum sulfur (S). The exact chemical composition depends on the applicable production standard and product thickness.

Mechanical Properties: Q355B seamless steel pipes offer a minimum yield strength of 355 MPa for smaller nominal thicknesses, a tensile strength of 470–630 MPa, and a minimum elongation of 21%. The specified yield strength decreases with increasing product thickness. Actual mechanical properties depend on the applicable standard, pipe dimensions, and delivery condition.

Applications: Q355B seamless steel pipes are commonly used in structural engineering, steel construction, machinery manufacturing, bridges, and industrial equipment. Their good strength and weldability make them suitable for load-bearing structures, mechanical components, and applications requiring reliable structural performance.

Quality Assurance: Our Q355B seamless steel pipes are available in various sizes and specifications to meet different industrial requirements. Chemical composition and mechanical properties can be confirmed through material test certificates, subject to the applicable production standard and delivery condition.

Note: Q355B is the current designation under GB/T 1591, while 16Mn is an older designation. The two grades are commonly associated but are not necessarily interchangeable in every specification. Final product requirements should be confirmed against the applicable standard and material test certificate.