OSG Diameter correction tool for thread mill DCT75 (Thread type: U/UNJ)

The effective diameter of the screw opening can be quantified, as it has been difficult to measure it up until now.
How to use <Part 1>: Easy and simple measurements can be made visually.
How to use <Part 2>: Calculations can be made by measuring height. (The calculation formula varies depending on the screw size)
How to use <Part 3>: Simply place the digital display over the DCT75 to display the calculation results digitally. (option)
The shape is set so that 2B accuracy can be measured, so it can be used as is for 3B.
The effective diameter of the female thread opening is quantified. Simple visual measurements and height measurements can be used for calculations.
*If the female thread is a blind hole, please make sure that the female thread length is longer than the DCT75 thread length.