Produced through propriety melting and refining process, Marshalloy MQ/FM Alloy Steel is suitable for plastic injection mold applications as well as short run tools and dies. P-20 is decarb-free, stress-relieved, and tested to rigorous standards to ensure uniformity of structure and low inclusion levels. Pre-hardened to 262/321/BHN, steel has balanced composition that ensures uniform cross-sectional hardness and maintains specified hardness throughout plate.