I use the following for my drawings: These numbers go back to my board drafting days.
.35 mm for thin lines (.0138")
.5 mm for medium lines (.0197")
.7 mm for thick lines (.0276")
I hope that helps.
Thanks for your reply.
I myself use 0.5 mm for sheet border (the frame), 0.35 mm for visible edges and tables exterior lines and 0.18 mm for hidden edges and interior table lines.
But I am trying to know if ASME or ISO prescribe actual requirements for sheet border and table lines or if it is left free.
Unfortunately, we don't have a copy of ASME standards here. I can't give you an official answer.