Imperial UNJF Plug Thread Gauges.

What are Imperial UNJF Plug Thread Gauges?

Imperial UNJF (Unified National Fine - Controlled Root Radius) Plug Thread Gauges are precision tools designed to inspect and verify the accuracy of internal threads manufactured to UNJF standards. UNJF threads are defined by their fine pitch and controlled root radius, which increases fatigue resistance and provides a stronger thread profile. These gauges ensure that tapped holes, nuts and other internally threaded components meet strict dimensional tolerances for compatibility with UNJF threaded counterparts.

How Imperial UNJF Plug Thread Gauges Work

Imperial UNJF Plug Thread Gauges are used to test the quality of internal threads by threading the gauge into the tapped hole. The "Go" gauge ensures that the thread meets the minimum size requirement by fitting smoothly, while the "No-Go" gauge ensures the thread does not exceed the maximum tolerance by failing to fully engage. This two-step process is essential in industries such as aerospace, defence and automotive manufacturing, where thread integrity is critical. For example, these gauges are often used to verify threads in engine components and high-stress assemblies, ensuring secure and reliable connections.

What Material Imperial UNJF Plug Thread Gauges are Made From

These gauges are typically manufactured from hardened tool steel or high-grade alloy steel. Tool steel is chosen for its exceptional durability, wear resistance and ability to maintain precise dimensions over repeated use. 

FAQs

Q: What is the difference between UNJF and UNF threads?

A: UNJF threads feature a controlled root radius, which increases fatigue resistance and thread strength compared to standard UNF threads.

Q: Why are Imperial UNJF Plug Thread Gauges important?

A: These gauges ensure internal threads conform to UNJF standards, guaranteeing compatibility and reliable performance in high-stress assemblies.

Q: How often should UNJF Plug Thread Gauges be calibrated?

A: Regular calibration is recommended to maintain accuracy, particularly for gauges used frequently or in critical applications.

Bespoke Imperial UNJF Plug Thread Gauges Manufacture.

High precision, bespoke manufacture of Imperial UNJF Plug Thread Gauges to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.