420 / | HD | ALLOYS OR METALLIC COMPOSITIONS |
8 | DF | FERROUS (I.E., IRON BASE) {24} |
34 | DF | .~ Nine percent or more chromium containing {14} |
42 | .~.~ Over 0.05 percent sulfur, over 0.04 percent phosphorus or sulfur or phosphorus added in any amount to promote machinability |