I agree with not getting too hung up on paint names, but trust your eyes to get the tone you want/need for your specific project. Steel looks many ways; is it new or old, pressed, cast, extruded, sanded, brushed, or otherwise treated? A "steel" paint could be a starting point, but might seldom be the finishing point. I like to use good ol' Testors in the little square bottles, and mix as needed. I like to start with Flat Aluminum, Flat Steel, and Flat Gunmetal, and mix as needed. Don't be afraid to mix in some Brown,Gray, Black, or White in flat or gloss to achieve a warm or cool tone to mimic the appearance of just about any metal you need. Don't be afraid to use non-metallic paint to get the look of metal, either. Sometimes steel just looks dull gray, and metallic sparkle is not more accurate, just different. Trust your eyes and remember; you are not making metal, but just the appearance of metal. If it looks dark gray, paint it dark gray.