In most cases, the DIN 40430 standard is used for this type of thread gauges. Our gauges are made in accordance with this German standard. See also UTE 68.312 for information: it does not contain exactly the same values for thread but offers supporting information.
There are no different classes of tolerance in DIN 40430. The values of PG define dimensions for internal and external threads, and they are shown in a table contained in the standard.
GO Threaded Plug Gauge: This gauge checks the minimum limit of the major diameter (D) and also verifies functionality (angle and pitch).
NOGO Plain Plug Gauge: This gauge checks only the minimum limit of the minor diameter (D).
GO Thread Ring Gauge: This gauge checks the maximum limit of the effective diameter (D) and the maximum limit of the minor diameter. It also verifies functionality (angle and pitch).
