Going back some time I'm afraid, but what I recall is:-
tapped hole, plan view is full circle as minor diameter (hole) with a 7/8ths circle surrounding it to represent the thread (edit - not what's shown in the link, guess they're right, I thought it was the other way round for a tapped hole i.e. the part circle is in the metal side of the detail) . Section is simply parallel lines at core diameter (hole size) and thread outer diameter. Core hole is longer in a blind tapped hole.
Bolt side view is full outline of outer thread diameter, parallel lines at thread minor diameter, transverse line across shaft at the full extent of the thread. A chamfered end is usually shown.
If that makes sense?
like this
http://www.roymech.co.uk/Useful_Tabl...omponents.html