plastigauge is a compact lightweight measuring device. It consists
of a thin strip of plastic thread which is available in different
in sizes, it is used for measuring clearances - especially on engines.
The Plastigauge is sandwiched between a clean bearing surface on
a shaft and the bearing itself which flattens the original shape.
The dimensional clearance is then determined by comparing the amount
that the gauge material has expanded or flattened using a template.