... mathematics, and engineering to the study of metals Metallurgy is the art and science of extracting metals from their ores, refining them, alloying them and preparing them for use, and studying their properties ... and, for professional positions, these grades are intended as training levels only GS-9, on the other hand, may be the full performance target grade for some work settings The most obvious GS-9 work ... opportunity for the exercise of independent judgment, simple and elementary work requiring professional, scientific, or technical training ” The standard This is the grade for basic trainee positions in...