What Is AISI H21 Tool Steel and When Should You Use It?
Introduction When your tools face sustained heat—hot extrusion dies, large forging tools, or high-volume plastic molds—you need a material that keeps its strength and shape. Ordinary tool steel softens or cracks under these conditions. AISI H21 tool steel solves this problem. It is a chromium-tungsten-molybdenum hot-work steel designed to perform at temperatures up to 600°C. […]














