The parts of any machine are typically brought together by special fastening units that can withstand stronger stress than usual. These fastening units usually include bolts and screws. The most important part of these units is called the thread, and it has to be made sure that the thread is perfectly created in order to serve its function. Thread ring gauges are used to find out if a certain screw or bolt is useable or not.
These thread gauges used in metrology are ring-shaped tools typically made of steel and is used to check externally threaded parts. It comes in different sizes and can even be customized to suit your needs.
The purpose of this tool is to check all the elements of the thread and see if everything is in accordance to the specifications needed by the machine engineer. These gauges can check the angle of the thread and the thread pitch or the distance between threads.
It cannot be used for checking nuts or any other item in which the thread is located on the inner part.
How it works
The ring gauge tests the screws or bolts through the GO and NO-GO test.
To see if the screw is acceptable, it has to go through the GO ring gauge easily, without forcibly twisting it. All the threads on the screw must go through the GO ring gauge.
The GO ring gauge also makes sure that the externally threaded bolt fits into its internally threaded counterpart. It makes sure that the diameter, pitch, and angle of both items are the same.
At the same time, it must not be able to pass through the NO-GO ring gauge. If it does, then the ring gauge must only be able to do at most two rotations for it to still be rendered acceptable. Otherwise, the screw will not be acceptable for use.
Kinds of thread ring gauges
There are two kinds of thread ring gauges available for use – the solid thread ring gauge and the adjustable thread ring gauge.
The only difference between the two is that the adjustable gauges have a spilt in one part of the ring and a locking screw facility which enable the thread gauges to adjust to the diameter of the screw. A master gauge or a setting plug is used to set this certain type of gauge.
These tools must be given ample care since they play a very important role in the fabrication of machines.
Since they are usually made of steel, it is important to wipe thread gauges with oil after using them or any other formula that could help prevent the tool from rusting. Aside from this, make sure to check if your thread ring gauges are still properly set and calibrated to avoid any problem with incorrect measuring.