Ferrous (i.e., Iron Base) Patents (Class 420/8)
- Noble metal containing (Class 420/35)
- Cobalt containing (Class 420/36)
- Rare earth containing (Class 420/40)
- Lead, bismuth, antimony, calcium, selenium or tellurium containing (Class 420/41)
- Over 0.05 percent sulfur, over 0.04 percent phosphorus or sulfur or phosphorus added in any amount to promote machinability (Class 420/42)
- Eight percent or more nickel containing (Class 420/43)
- Eight percent or more total nickel plus manganese containing (Class 420/56)
- Copper containing (Class 420/60)
- Over 0.1 percent aluminum containing (Class 420/62)
- Boron containing (Class 420/64)
- 0.25 percent or more nitrogen containing (Class 420/65)
- Molybdenum or tungsten containing (Class 420/67)
- Group IV or V transition metal containing (Class 420/70)
- Processes (Class 420/71)