Thread gages—also known as pitch gages—are used to check the pitch of a thread (the helical structure) on a screw or a working piece's hole.

Gauges are designed as per Taylor's Principle.The 'GO' gauge is designed to check Major, Minor & pitch diameters., the NO GO gauge checks only 

Plug gauges are used to check internal threads, whereas ring gauges are used to check external threads. Each gauge comprises of two parts: a GO gauge and a NO GO gauge. Both parts should be used to check the thread. Is standard for thread plug gauge? Thread set plug gages are manufactured to X tolerances in class 1A, 2A, and 3A for go members

A GO thread plug gauge is used to check the finished size of an internal thread by means of checking the major diameter as well as the pitch.

Taper plug gauges are used to check tapered holes. It has two check lines. One is a GO line and another is a NOGO line. During the checking of work, NOGO line remains outside the hole and GO line remains inside the hole. These gauges made with standard or special tapers are used to check the size of the hole and the accuracy of the taper.

How To Use Thread Gages (UN, UNJ and Metric styles) Basics of Using Go & No/Go Plugs & Rings. The Secrets of UNJ Thread Gages No One Ever Told You (MIL-S-8879 Superseded by SAE-AS8879) A simple method to check if the thread plug is due to be replaced from wear is the method shown below. This is a relatively simple method to confirm the PD

There are plug gauges for straight cylindrical holes, tapered, threaded square and splined holes. At one end, it has a plug of minimum limit size, the ‘GO’ end and; at the other end a plug of maximum limit, the ‘NOGO’ end. Snap gauges are used for checking external dimensions. Shafts are mainly checked by snap gauges.

There are also threaded plug gauges that are used to check threaded or tapped holes, and verify the proper thread type, major diameter, minor diameter, 

A Standard Thread Plug Gage refers to an inspection tool used to check a workpiece against its allowed tolerances via a go/no-go test. For example, ISO 1502 sets a standard for screw

2016. 8. 15. · Working thread plugs are to be used in an internally threaded hole and are not to be used to check a ring gage. The part being checked is generally acceptable when the NOGO work plugs does not enter more than 1 1/2 to 3 turns dependent upon customer specifications and the GO work plug freely enters the threaded hole in its entire length. In addition to the passing the

A class 2B working plug gage is used to inspect a class 2B internal product thread. A Class 6H metric internal thread is inspected with a class 6H go / no-go working plug gage. Truncated setting plug gages for adjustable thread ring gages tend to cause some problems and confusion. Many of these problems are due to misunderstanding the purpose