Size the gauge (sizing) plate for a gauging pig. Enter pipe OD and wall; get the ID and the plate diameter at 90-95% of ID.
Gauge / Sizing Plate
A gauge (sizing) plate is a thin aluminum disc mounted on a gauging pig to prove minimum bore and detect dents, buckles or ovality. Standard is 90-95% of pipe ID (95% typical for a proving run), usually 1/8-1/4 in aluminum so it deforms on contact. Always confirm the percentage against the project specification.