Karfe Farko

An yi kusoshi da tagulla ko ƙarfe na ƙarfe kuma maƙera da ƙusoshi ne suka yi su.Wadannan masu sana'a sun yi amfani da sandar ƙarfe mai zafi mai murabba'i wanda suka ƙirƙira kafin su dunƙule sassan da suka zama aya.Bayan an sake yin dumama da yanke, maƙerin ko ƙusa ya saka ƙusa mai zafi a cikin buɗaɗɗen buɗaɗɗen ya yi masa guduma. Daga baya kuma an ƙirƙiri sababbin hanyoyin yin ƙusoshi ta hanyar amfani da na'urori don warware ƙusoshin kafin a karkatar da sandar a gefe don samar da shank.Misali, an yanke ƙusoshi na Nau'in A daga nau'in guillotine na ƙarfe ta amfani da injinan farko.An ɗan canza wannan hanyar har zuwa shekarun 1820 lokacin da aka buga sabbin kawunan kan ƙarshen ƙusoshi ta hanyar na'ura daban.A cikin 1810s, an jujjuya sandunan ƙarfe bayan kowace bugun jini yayin da saitin yanke ya kasance a kusurwa.Daga nan an yanke kowane ƙusa daga taper don ba da damar kama kowane ƙusa ta atomatik wanda kuma ya zama kawunansu.[15]An halicci nau'in kusoshi na B ta wannan hanya.A shekara ta 1886, kashi 10 cikin 100 na kusoshi da aka yi a Amurka sun kasance na nau'in kusoshi masu laushi na karfe kuma a shekara ta 1892, kusoshi na waya na karfe sun mamaye ƙusoshin da aka yanke na ƙarfe a matsayin babban nau'in ƙusoshin da ake samarwa.A cikin 1913, kusoshi na waya sune kashi 90 cikin 100 na duk kusoshi da aka samar.

Kusoshi na yau yawanci ana yin su ne da ƙarfe, galibi ana tsoma su ko kuma a rufe su don hana lalata a cikin yanayi mai tsauri ko don inganta mannewa.Kusoshi na yau da kullun don itace yawanci suna da taushi, ƙarancin carbon ko “ƙarfe mai laushi” (kimanin 0.1% carbon, sauran baƙin ƙarfe da watakila alamar siliki ko manganese).Kusoshi don kankare sun fi wuya, tare da 0.5-0.75% carbon.