Ahh, so you meant to use "83,000 PSI" and instead you used "83KSI."
In some regions, the soil is very rocky, so you start pounding a weak stake in until it hits a rock and bends. If you start with stronger and harder stakes, it will withstand the buried rocks. My point is that a titanium stake will survive a lot longer than an aluminum stake. In regions with soft soil, aluminum would be OK.