銑鉄[sentetsu] pig iron
白銑[hakusen] white pig iron

鎔銑[yousen] molten iron
製銑[seisen] pig iron making

研鑽[kensan] diligent study
鑽り火[kiribi] striking sparks with flint and steel or by rubbing sticks together (usu. to start a fire)
鑽孔機[sankouki] boring machine
鑽り出す[kiridasu] to quarry

鑽孔[sankou] boring
鑽る[kiru] to start a fire (with wood-wood friction or by striking metal against stone)
自己研鑽[jikokensan] self-improvement
火鑽り[hikiri] hand drilling (to start a fire)