Bolt head/Wrench size to bolt diameter conversion chart:
Standard recommended torque spec for each size bolt:
Conversion factor based on bolt condition (reduce by 30% for heavily greased [anti-seized] bolts):
Coefficient factor indicates bolt condition (k factor indicates dry, vs lubed, vs greased, etc), koken chart is based on k = .2 which is generally new and dry).
Newton Meters (NM) to Foot pounds (Ftlb):
OEM BMW torque specs based on bolt size:
Conversion chart from Metric to SAE and British:
Chart to identify different types of new world bolt heads: