SA 387 GR 12 CL 1 / CL 2 – Chrome-Moly Steel for Reliable High-Temperature Pressure Service SA 387 Grade 12 Class 1 and Class 2 plates are alloy steels containing approximately 1% chromium and 0.5% molybdenum, developed for pressure applications involving moderate to high temperatures. These plates are known for their thermal stability, oxidation resistance, and dependable mechanical strength, making them a preferred choice for boilers, heat exchangers, and petrochemical vessels. While Class 1 meets the requirements of general elevated-temperature use, Class 2 is suitable for environments demanding greater tensile and creep strength. Key Benefits: Thermal Strength and Longevity: Designed to operate efficiently at temperatures approaching ~600°C, maintaining strength and structural integrity over extended periods. Resistance to Oxidation and Mild Corrosion: Effective in hot steam or mildly reactive chemical environments, thanks to Cr-Mo alloying. Class Variants for Flexible Design: Choose Class 1 for standard high-temp pressure work or Class 2 for more demanding applications with higher mechanical stresses. Good Weldability and Machinability: Compatible with common welding practices and easy to fabricate when proper preheat/post-weld treatments are applied. Mechanical Properties Snapshot: Property SA 387 Gr 12 Cl 1 SA 387 Gr 12 Cl 2 Yield Strength ≥ 205 MPa ≥ 220 MPa Tensile Strength 415–585 MPa 515–690 MPa Elongation ≥ 20% ≥ 18% Max Service Temp Up to ~600°C Up to ~600°C Typical Applications: High-pressure steam vessels and drums Thermal processing units and reformers Refinery exchangers and preheaters Piping systems for hot gas and steam flow Summary: With its proven performance under heat and pressure, SA 387 GR 12 CL 1 / CL 2 is a versatile material for critical pressure components in power, refining, and chemical industries. Its solid fabrication properties and dual strength classes provide both flexibility and durability for engineers designing high-performance systems.