Good gear from this supplier, and quick hassle free delivery too. They will be A2 grade stainless, which is good enough for a car. A4 grade (marine/food) is better quality with less iron in, but many of the sizes are hard to get hold of.
Here is the spec of the charger pivot bolt from them:
M12 x 110mm Socket Capscrew
ISO Coarse thread
sale quantity one unit
Major Diameter 12.00mm
Thread Pitch 1.75mm
Length under head 110mm
Thread Length 36mm
Hex Wrench Size 10mm
Cap Height 12mm
Cap Diameter 18mm
Thread Included Angle 60°
Material Grade A2-70 (304)stainless.
Manufacture Cold-forged, Rolled Threads
Applicable Standard DIN912
Alternative nomenclature Allen Screw
Cold forged with rolled threads = good gear