How is tool life typically measured in milling?

Tool life in milling is typically measured by the number of parts machined or the amount of time the tool remains effective before it needs to be replaced or sharpened. This metric is critical as it helps in evaluating the tool's performance and efficiency over its operational lifespan. The number of parts produced gives manufacturers a clear indication of how long a tool can maintain its cutting effectiveness before becoming dull, while time measurement allows for tracking wear and ensuring optimal production schedules.

Measuring tool life in terms of parts machined or duration ensures that machinists can make informed decisions regarding tool replacement, potentially leading to improved productivity and reduced downtime. This data is essential for optimizing processes and maintaining quality in manufacturing operations, as it directly impacts operational costs and effectiveness. In contrast, other options do not provide relevant measures of tool performance in the context of milling operations.