Understand Screw Pitch for Bolts (UNC Vs UNF)

My videos are related to QA/QC engineer for all disciplines. Most of them are from API ( 510/570 & 653), ASME sec ( V, VIII Div-1 & IX), welding, painting & piping, CSWIP / Bgas / NDT level -II, valves, pump alignments, materials, different types of tests related videos. I tried to share the knowledge with persons either involved in similar industries or starting a career in this. Few of my videos are also related to Auditing / NCR formats too.