Not my experience.
Specify a high tensile hex head set screw you get 8.8. 10.9 seems to be a special order. We use 10.9 hex head screws in one particular place in one of the machines we produce - sometimes difficult to get.
What's even more difficult is getting fitters to read the entire part note and not stop reading at the bolt thread and length, wander off to the bolt rack, get our stock 8.8 ones, install them and tighten to the higher torque specified on the drawing for the correct 10.9 . . . few months down the line after customer commissioning and there's a failure in the machine requiring some serious dismantling to get to.
