Telecom Cables used in highly sensitive service are usually twisted pairs with individual shields and then an overall shield,shields should only be terminated at one end.Some component manufactures recommend different ways.
The method I have used most is to terminate the individual shield on the card and the overall shield land on the chassis ground and this is adequate for EMI/EMF.....
The metal nuts and bolts you speak of IMO is not something that needs to be considered.EMI/EMF is interference of one cable to another, ie
ower cable in close proximity to an instrument cable.,large metal structures also may give some trouble but shielding is usually adequate.
Shielded twisted individual pairs or triads are often run in rigid metal conduit with no ill effects if the shields are handled properly.I have Cat5 cable running all over my house with out any problems,tho I have attempted to keep the electrical cables separated and tried to cross only at 90 degree angles rather than run parallel.
I am interested to hear others and their thoughts on your question.
dick