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)

せん状骨[senjoukotsu] scaphoid bone (in wrist near thumb)
遺骨[ikotsu] remains
化骨[kakotsu] ossification
会厭軟骨[eennankotsu] epiglottis
がい骨[gaikotsu] skeleton

雁骨[kariganebone] scapula
気骨[kikotsu] (moral) backbone
侠骨[kyoukotsu] chivalrous spirit
胸骨[kyoukotsu] breastbone
筋骨[kinkotsu] muscles (sinews) and bones