McMaster 6851N21 Gray Plastic Clearance Gauge, Pack of 10

Squish these tiny plastic strips between two components to measure the clearance between them. Once compressed, match the widest part of the flattened strip to the markings on the reading card. Each marking on the card corresponds to a different clearance measurement. For large bearings and wide surfaces, use two or more strips to check for inconsistency.

Originally designed to check clearances in automotive bearings, these strips also work with cylinder heads, flanges, and other fitted parts. Although generally less precise than calipers and hole gauges, they take clearance measurements in spots that can't be reached after the part is assembled.