What are the features and uses of UNF thread gauges?


The terminology of thread gage can get confusing for people who are not related to the profession. Thread gauge is a tool that measures and inspects screws and bolts along with other things. When you produce hardware you need accurate tools to inspect the parts that are going to be used in final product and to examine cylindrical objects. For example in shafts or holes you need a GO and NO-GO snap gauge ring gages and plug gages respectively. 

The thread gauges are used in examinations for determining thread’s major diameter, minor diameter, pitch diameter, pitch (in case of metric threads) or threads per Inch (TPI in case of Standard American Equivalent (SAE) threads), flank angle, etc. The product is considered passed if the GO gage is answered even if NO-GO gauge is not answered.

There are thread plug gauges which are used for inspection of the nut, an internal thread part. Then there is thread ring gauges which are used for inspecting external screw threads of manufactured parts. Both these gages have two parts, GO gage and NOGO gage which is joined by double ended rod with each end carrying the parts. But it is only useful for small threaded parts and the larger parts needs two separate GO and NOGO gages. Using this tool you can easily pass through the entire length of the nut without needing much rotational force. It enters the nut from both sides checking in no more than 2 turns.

Different types of thread gauges that are manufactured and sold in the market

These gauges and tools are usually manufactured and sold by same company.  Gausgestools is a noteworthy manufacturer of high quality thread gauges and taps. The company offers standard sized gauges and also customized versions that are made to suit client’s requirements perfectly. On their official website they provide multiple categories for thread gauges and each category contains abundance of products in different sizes and features. If you are looking to purchase a thread gauge this website is a good spot to stop at and search for the tool you need.  

One of the popular products that the company offers is Unified National Fine thread gages also known as UNF thread gages. Fine thread series-UNF is suitable where coarse series is not ap        plicable along with the production of bolts, screws, and nuts and for other applications. Thread coarse series and fine thread series has a greater tensile stress area in contrast to other thread series. In addition to that another advantage of this series is its suitability to stripping of resistance both external and mating internal threads equals or exceeding the tensile load carrying capacity of the externally threaded members.

All of the UNF thread gages are manufactured in compliance to ASME B1.2, each gauge 100% calibrated with quality assurance. They use high quality material of oil hardened tool steel-Gcr15 that has high wear resistance. It has a hardness of 58-62 HRC level with every gage being tested and these products come with SO9001 certification.