https://www.google.com/search?q=aircraft+bolt+chart&biw=1003&bih=581&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjuisWomp7PAhXBVT4KHbBMAVAQsAQITQ

http://www.metricbolt.com/metric-fasteners-for-aerospace/

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html