an easy way to make threated holes (3/8" BSP or GAS). what does it mean UNF and UNC close to ISO and values like7/8-14? thanks for help
UNF is Unified Fine
UNC is Unified Course
See this wiki page: Unified Thread Standard - Wikipedia, the free encyclopedia
7/8-14 is a .875 inch outside diameter with a 14 threads (pitch) per inch.
ISO threads are the same way: 6-.0.75 is a 6mm outer diameter with a 0.75 pitch for the thread spacing.
You can create your own thread (.hol) files by following the setup of an existing file.