The no-go gauge is used to detect the maximum limit of the contact thread, which is to ensure an accurate fit with the matched bolt that is imperial Class 2A and metric 6g.
    The application method of ramp no-go gauge:
    a. If the ramp no-go gauge does not enter into the threaded hole, the thread is acceptable.
    b. If the ramp no-go gauge enters into the threaded hole no more than three teeth, the thread is acceptable. If there are special requirements, such as thinner or ductile materials, and a few number of threads, we can make the necessary adjustments for this request. Blockage is the result of metal contact. Do not apply a force on it by hand under any circumstances when no rotation of the gauge.
    The application method of pitch diameter no-go gauge:
    a. If the ramp no-go gauge does not enter into the threaded hole, the thread is acceptable.
    b. Suppose the case of blockage, that if the no-go gauge fully gets through the thread is acceptable. In the case of blockage, do not urge force on the no-go gauge. If there are special requirements, such as thinner or ductile materials, and a few number of threads, we can make the necessary adjustments for this request.
    30° variable tooth type locking thread gauge is the main basis for determining the quality of 30° variable tooth type locking thread. In order to prevent the long-term use of wear and tear of the product, recommend for gauge calibration on a regular basis.

Pitch diameter no-go gauge threaded portion enlarged view  

Slope no-go gauge threaded portion enlarged view