Toolmakers Microscope 

Very good explanation sir in easy way.🎉

Very good explanation sir. Thanks

Well done bro thank you

Sorry to use such language. But u r very intelligent person. Just shut the persons with background talking out of ur class

if we place flat thread rolling die and light is on the top surface can measure root flat

clearly visible..thanks

How to check Root flat of a thread , of a thread rolling dies

Thumbs up. Thank you. Now I know.

Are sir readings to de do, experiment karna h

your looks and accents are like that of a driver. brownie

It's shame for u. U r having group of goons behind u & back talking