Speaking of Steel...
KNOW YOUR STAINLESS STEEL
-200 Series: austenitic chromium-nickel-manganese alloys
-300 Series: austenitic chromium-nickel alloys
-400 Series: ferritic and martensitic chromium alloys
-500 Series: heat-resisting chromium alloys
-600 Series: martensitic precipitation hardening alloys
Read the Wikipedia article.