Threaded gauges

Threaded plug gauges

Thread gauges and differential gauges are essential tools for dimensional control of threads in various industrial sectors. These measurement instruments allow verification of the conformity of threads to the tolerances specified by the reference standards, ensuring quality, precision, and interchangeability of components. The "GO" thread gauge is used to ensure that the thread of a part is correctly manufactured and falls within the lower tolerance limits, enabling smooth engagement without abnormal resistance. The "NO-GO" thread gauge, on the other hand, checks that the thread does not exceed the upper dimensional limits; if it fits, the part is out of specification. Also available is the "GO/NO-GO" thread gauge, which combines both functions for fast and comprehensive inspection, ensuring that the part meets all tolerances.

Another category of inspection tools includes differential gauges for specific threads. The differential ring gauge for American tapered GAS threads (NPT) is used to verify that the tapered thread complies with specifications, which is essential for ensuring tightness in applications requiring hydraulic or pneumatic sealing. For NPTF threads, which must ensure a dry seal without the use of sealants, the GO/NO-GO differential plug gauge allows simultaneous control of the diameter, pitch, and thread profile.

These tools are applied to a wide range of threads, including BSPT (British Standard Pipe Taper), BSW (British Standard Whitworth), UNC (Unified Coarse), UNF (Unified Fine), GAS (cylindrical threads), tapered GAS, TPN trapezoidal threads, M ISO metric threads, and MF ISO fine metric threads, as well as American standards NPT and NPTF. Each thread type has specific technical characteristics requiring dedicated inspection tools to ensure compliance.

The primary users of thread gauges and differential gauges include quality control operators, production technicians, and industrial maintenance professionals. These tools are widely employed on production lines to ensure that parts meet dimensional standards, in metrology laboratories for precision inspections, and in specialized industries such as oil and gas, hydraulics, pneumatics, and automotive. Their application helps prevent defects, improve the reliability of threaded joints, and ensure the safety of systems where they are used.