Usually the thread detection GO failure the following two situations are more common:

①, tooth injury leads to GO impassability.

300 series stainless steel products due to the soft characteristics of the material, in the production, transportation and other mobile process is easy to produce tooth damage, at present, the entire industry there are small external thread tooth damage. When this kind of slight tooth injury, it is recommended to exert a little force, and the ring gauge can be passed, which can be regarded as qualified.

(The standard allows rotation with a certain force, and if it can pass, the batch of products is qualified. The content can refer to the torque specified in GB/T 5779.1-2000, specifically see the following table)

2, the difference between old and new measuring tools

a) Measuring tool tolerances produced by different measuring tool manufacturers are different. For example: the same batch of products A brand of measuring tools can pass, but B brand of measuring tools GO is not smooth.

b) New and old measuring tool tolerances are different. For example, GO is not smooth when tested with a new gauge, but it passes with a qualified old gauge.

The basis for this batch of qualified products: ASME B1.3M standard stipulates that "two qualified ring gauge tests, one of which passes the ring gauge test will determine that the batch of products is qualified." For example, the same batch of products can not be tested with A ring gauge, but can be tested with B ring gauge. As long as the B gauge is qualified, this batch of products is judged to be qualified.