Babban abin ƙyama da sannu da kyau sosai gunagara galibi ana yin su ne da ƙarfe Ingot, wanda za'a iya kasu kashi mai yawa bisa ga ƙayyadaddun ƙarfe na ƙarfe. Gabaɗaya da taro ya fi 2T ~ 2.5t, diamita ya fi girma 500mt ~ 550mm Ingot da ake kira Babban Karin Magot, wasu kaɗan ne kadan.

Latsa mai gamawa Ingantawa da aka yi amfani da shi kafin zafin jiki na tsawan wutar lantarki da zazzabi mai zafi, kuma Ingantaccen dumɓu a ƙasa, da sauƙi don ingancin yanayin zafi, kuma Ingantaccen dumɓu-dumɓu, da sauƙi don crack. Saboda haka, a cikin ƙarancin zafin jiki na Ingant mai narkewa, zazzabi mai ɗorewa kuma ya kamata ya iyakance.
Marka da tsananin dumama manot tare da ƙayyadadden bugun dalla-dinin da yawa, saboda saurin zafin jiki na iya zama da yawa, saboda haka saurin tena ya kamata ya zama da sannu a hankali. Misali, don carbon tsarin karfe da Alliy clect/hercid, da zazzabi na wutar lantarki gabaɗaya ne 350 ℃, girman girman karot yana da girma, kuma rufin karfi. Ga siloy karfe, kamar babban saurin ƙarfe, babban ƙarfe Chromium yana da sauƙi don crack lokacin da ya kamata a sarrafa zazzabi a 400 ℃. Lokacin da zazzabi ya fi 850 ℃, za a iya mai zafi a cikin sauri sauri, amma ba da sauri, don guje wa abin da ya faru na cirewa da waje da bambancin zafin jiki ya yi yawa. Misali, ka mara da tsarin ƙarfe mai ɗorewa da Alloy tsarin ƙarfe ba da izinin bambancin zafin jiki tsakanin 50 ℃ da 100 ℃.
A lokacin da dumama kananan karfe, saboda karamin sashi girman, abin damuwa na saura da kuma saurin carbon na iya zama babba, ana amfani da wani sashi na carbon na carbon. Don kananan ƙananan girman karfe, saboda ƙarancin yanayin zafin jiki mara kyau ne, kuma babban dulasen Ingot na da a 700 ℃ 1000 ℃ zazzabi tfita.
Domin rage lokacin dumama kuma adana mai, babban kara daga wurin bita na karfe bayan tsintsiya, da kai tsaye aika zuwa ga mashin meerce dumama, wannan nau'in erote erote dumama, wannan nau'in erote erote dumama. A lokacin da zafi mai tsananin farin jini caji, sararin samaniya na 550 ℃, saboda yawan zafin jiki na iya zama ɗaya, saboda cajin wutar tandere na iya zama ɗaya daga cikin tsananin dumama mai girma.