This two-day course focuses on the GD&T gage development and application, including gage principles, gage design, dimensioning and tolerancing, gage usage, fixture development, gage tolerancing policies. Gage is an important tool to inspect the GD&T requirements per ASME Y14.5M-1994 and ISO1101 GD&T standard. The structure and tolerancing principles of the gage will greatly affect the product quality level. The correct gage principle will reduce the measurement risk, including the conforming parts rejection and nonconforming parts acceptance.