@skylar @udongle And as an example of what I mean: Fatigue limit. Imagine a piece of steel that could handle X force at max before failure. There is a number, hypothetically 0.3X for example purpose, where the steel can handle the force forever and never deform or lose strength or fail or fatigue in any other way. Aluminum doesn't have this property. The only metals with a fatigue endurance limit are iron and its alloys (steel), and titanium.