the most common failure on a Bosh SPS drill is the actuator arm for the pounding motion, and this is commonly shared among several power tool brands with SPS drills.

you could make the argument that these parts just fail more often, and if you go by what broke, that would make you think it's a reasonable conclusion.

Until I tell you that said actuator arm is made of injection mold plastic and all other parts of this assembly are made of steel. So in reality, this part that just happens to break more often is doing so because it was meant to, we are more than capable of creating contact terminals that don't break as easily