Threads are a common Feature used to fasten Components in real life. Sometimes you'll want to add Threads to your Model so that the Manufacturer may reproduce this part as desired. There are several methods for creating a Threaded Feature in SolidWorks
Menu Bar→Insert→Annotation→Cosmetic Thread→LMB Cylindrical Edge
Menu Bar→Insert→Feature→Thread→LMB Circular Edge→Select End Condition
Select Thread Type: