this tutorial will teach you how to use a screw gauge this device is used to measure small dimensions like thickness of fire bolt etc to an accuracy of 0.01 mm as you can see this is the main scale with each division equaling to one MA and this is the voltage with circular scale it has a number of divisions ranging from zero to 45 and a total of 50 divisions let's take an object from our slip gauge set it has a number of blocks with different dimensions we are taking a block of thickness 1.3 4 mm which is written over here now we'll put this object into our screw gauge in between this gap and we will rotate the circular pot slowly until it tightens up we'll keep an eye on the main scape we can see only one division left will write this down and on a circular scale we see the main scales line consulting with the report operation this will be our second really real note it down this circular scale has leased out of 0.01 now to get the total thickness of the object we need to do a little calculation and I'll compare with the objects thickness we find both the values to be same now you too can measure the dimensions with a screw gauge wasn't that easy no