Makers of King Tut thread (as well as other brands) Dr.Bob has the title of Chief Threadologist for the company and is a wealth of information.   They have various short videos running on their site and well worth a visit and a listen with your cup of coffee:

www.superiorthreads.com/videos

You’ll find lots under ‘Education’ and videos

The one I just watched was about doing the ‘snap test’ on older threads which is useful to know.