燧石[hiuchiishi] flint

燧鉄[hiuchigane] striker (triangular piece of steel used with flint to create sparks)

黄鉄鉱[outekkou] iron pyrites
可鍛鉄[katantetsu] malleable iron
狭軌鉄道[kyoukitetsudou] narrow-gauge railway
近鉄[kintetsu] Kinki Nippon Tetsudou (railway co.)
剣付き鉄砲[kentsukideppou] fixed bayonet

甲鉄[koutetsu] armor
甲鉄艦[koutetsukan] armored ship
甲鉄板[koutetsuban] armor plate
鋼鉄[koutetsu] steel
国鉄[kokutetsu] national railway (esp. Japan National Railways)