STEEL

(See also Metals)

ancient use: g63 6/8 23

discussion: ad 840

production: g63 7/22 30; g61 12/8 18; g57 11/8 16-20; g55 1/22 9-11; g30 6/25 617-618

ancient African technology: g78 12/8 29

China: g79 10/22 31

gap between United States and Soviet Union: g80 6/22 31

rust: g62 8/22 24-26

scrap: g74 3/22 30

spark testing: g76 5/22 24-26

usage by country: g73 8/22 31