"Guards on machine tools are meant to protect operators and bystanders from injuries caused by tools, workpieces, and fragments hurled out of the machine's working zone. When the protective guards cannot withstand the impact of these high-speed objects, workers can be injured. Future European product standards will set forth clear requirements for the impact resistance of guards, and draft standards now exist for turning machines, milling machines, machining centers, and grinding machines. The machine-specific impact resistance requirements presented in this article can help you specify the material and dimensions for guards on your machine tools."