Check out the 175 parts list. The part numbers for bolts all contain the size and diameter. For instance, a bolt or screw with part number ending "...0655" is a 6mm thread, 55 mm long.
As for pitches, all 5 mm threads are 0.9mm pitch; all 6mm threads are 1.0mm pitch,; all 8mm threads are 1.25mm pitch.
The 6mm and 8mm are the same pitch as modern bolts, but 5mm threads are coarser and modern 5mm bolts will not fit.
Hope that helps,
Graham