What is the difference between GO and NOT GO gauges?

GO and NOT GO gauges are used in engineering and manufacturing to check the dimensions and tolerances of parts. A GO gauge verifies that a part meets the minimum acceptable dimensions, meaning it should fit easily when tested. Conversely, a NOT GO gauge ensures that a part does not exceed the maximum allowable dimensions; if it fits, the part is deemed out of tolerance. Together, they help ensure that components will function properly in assembly.