What is the tool used to measure the side clearances of piston rings?

The tool utilized to measure the side clearances of piston rings is a thickness gauge. This tool is specifically designed to measure gaps and clearances with a high degree of accuracy. In the context of piston rings, the side clearance is critical to ensure proper fit and function within the piston and cylinder assembly.

Thickness gauges, which can come in various forms such as feeler gauges, allow for precise measurement of these small clearances, ensuring that the piston rings can expand and contract properly during operation without causing excessive wear or damaging the engine.

In comparison, calipers, although capable of measuring dimensions, are not ideally suited for measuring specific clearances due to their design. Micrometers are typically used for measuring larger dimensions with high precision but are not as practical for measuring gaps like piston ring clearances. Dial indicators are more suited for measuring linear displacement or runout rather than clearance measurements. Thus, the thickness gauge is the most appropriate tool for this application.