I agree with Gutentight, however, from a YM220/220D manual here are some values:
M8 grade 7t 17-22 ft lbs, grade 11t (10.9T) 22-25 ft lbs
M10 " " 33-43 " " , " " " 45-52 " "
M12 " " 58-72 " " , " " " 76-87 " "
M14 " " 87-108 " " , " " " 123-145 " "
M16 " " 123-152 " " , " " " 192-225 " "
M18 " " 174-210 " " , " " " 253-297 " "
M20 " " 238-297 " " , " " " 362-420 " "
I can't get this thing to come out right, hope you can figure out the grade 7t verses grade 11T (10.9T)
Also, 12mm socket fits M8, 17mm fits M10, 19mm fits M12, 22mm fits M14, 24mm fits M16, 27mm fits M18