A517 Grade 55 is a quenched and tempered alloy steel plate designed for pressure vessels, heavy engineering equipment, and fabricated structures requiring high strength and dependable performance. The heat‑treated microstructure provides an excellent combination of strength, weldability, and dimensional stability, making the grade suitable for demanding industrial applications. It is widely used in energy, mining, transportation, and equipment manufacturing projects where weight reduction and structural efficiency are important design considerations.

Chemical Composition

A517 Grade 55 is produced using a controlled alloy design that may include manganese, silicon, chromium, molybdenum, and other strengthening elements. Carbon content is carefully controlled to maintain weldability while achieving the required mechanical properties through quenching and tempering. Low phosphorus and sulfur levels improve steel cleanliness and fabrication quality.

Mechanical Properties

A517 Grade 55 provides a minimum yield strength of approximately 380 MPa (55 ksi) and a tensile strength typically ranging from 550–690 MPa. The quenched and tempered condition enhances structural consistency and provides dependable mechanical performance across a wide range of fabrication thicknesses. The material also offers good toughness and resistance to deformation under heavy loading conditions.

Size Range (Website 5 Standard Template)

Thickness: 3–150 mm
Width: 1220–4200 mm
Length: 5000–18000 mm

Stock & Processing Services

Cutting • Beveling • Welding preparation • Heat treatment • Custom fabrication for pressure vessel and engineering projects

Applications

• Pressure vessel fabrication
• Heavy engineering equipment
• Mining and material handling machinery
• Industrial processing systems
• Structural fabrication requiring high strength
• Energy and infrastructure projects