FAILURE MECHANISMS in tool and die materials that are very important to nearly all manufacturing processes are discussed in this article. A wide variety of tool steel compositions are used. Properties and selection of tool steels are described in the Section “Tool Materials” in Volume 3 of the 9th Edition of Metals Handbook; microstructures and metallographic techniques for tool steels are detailed in the article “Tool Steels” in Volume 9 of the 9th Edition of Metals Handbook. This article is primarily devoted to failures of tool steels used in cold-working and hot-working applications.
