The BSPP G GO/NO GO thread plug gauge G 2 - 11 is designed for fast dimensional inspection of internal cylindrical pipe threads according to ISO 228, commonly used on fittings, hydraulic and pneumatic components, lubrication systems, manifolds, turned small parts and mechanical components where thread conformity is essential for coupling, mechanical sealing and interchangeability. The GO/NO GO method enables the operator to verify immediately whether the threaded hole is within the required functional limits, without measuring every geometric parameter with complex instruments. The GO side should screw smoothly along the effective thread length, without forcing, jamming or abnormal resistance; the NO GO side must stop and must not engage the thread beyond the permitted limit defined by the inspection procedure. This makes it possible to detect undersized, oversized, deformed, incomplete or damaged threads quickly, reducing inspection time in workshops and quality departments. The gauge is manufactured from high-quality hardened tool steel with a hardness of 58 HRC ±2 HRC, an important feature for dimensional stability, wear resistance and reliable repetitive checks on production batches. The threaded contact surfaces are accurately manufactured and finely finished to promote regular engagement in the hole and a clear inspection result. It is suitable for toolrooms, machining workshops, turning departments, production areas and quality control teams that need rapid checking of BSPP cylindrical threads on single parts or production runs. For correct use, the threaded hole should be cleaned before inspection, chips, oil and burrs should be removed, the gauge should be screwed in on-axis without using levers or excessive torque, and the result should always be interpreted according to the function of the two ends. Accredia certification or, alternatively, a calibration report can be supplied on request; this documentation may delay delivery because the instrument must be sent to the inspection or certification body.