What tool may be used to check the stem on a poppet-type valve for stretch?

A micrometer is an ideal tool for checking the stem on a poppet-type valve for stretch because it provides highly precise measurements of small dimensions. The design of a micrometer allows for accurate assessment of the diameter of the valve stem or its length. When a poppet valve is subjected to operational stresses, the stem may experience elongation, and measuring this change in length with a micrometer can help determine if the valve is still within acceptable limits for safe operation.

The high-resolution capability of a micrometer makes it suitable for measuring the minimal changes that occur due to stretch, ensuring that the valve can function properly and maintain sealing capabilities. Thus, using a micrometer is essential in applications where accuracy is critical, such as in adjusting or diagnosing mechanical parts like a poppet valve.