If you want to measure an unknown gap, you can interchange feeler gauges until you find the one or more that fits snugly into the gap and total their thickness to measure the gap.

Question

Quizplus · Accepted Answer

Feeler gauges are designed to measure gaps or clearances by inserting different thickness blades until a snug fit is achieved, allowing for an accurate measurement of the gap.

If You Want to Measure an Unknown Gap, You Can