Gabatarwa na ƙirƙira buɗaɗɗen bit na musamman
Forging wani nau'i ne na ƙarfe wanda ake sanya billet ɗin ƙarfe mai zafi ko ingot a cikin injin ƙirƙira sannan a datse shi, dannawa, ko matse shi da ƙarfi don siffanta shi yadda ake so. Ƙirƙira na iya samar da sassan da suka fi ƙarfi kuma sun ninka fiye da waɗanda aka yi ta wata hanya kamar yin simintin gyare-gyare ko injina.
Bangaren ƙirƙira wani sashi ne ko ɓangaren da tsarin ƙirƙira ke samarwa. Ana iya samun sassa na ƙirƙira a masana'antu da yawa waɗanda suka haɗa da sararin samaniya, kera motoci, gini, masana'antu, da tsaro. Misalan sassa na ƙirƙira sun haɗa da gears. Crankshafts, sanduna masu haɗawa. Ƙunƙarar harsashi, bit sub da axles.