Chitsulo cha Gray cast, chomwe chimagwiritsidwa ntchito kwambiri popanga makonda mwa kuponyera mchenga wobiriwira, kuponya nkhungu kapena njira zina zowuma mchenga, zimakhala ndi kuuma kolimba kwa makina a CNC. Iron imvi, kapena chitsulo chotuwira, ndi mtundu wachitsulo chopangidwa ndi graphite microstructure. Amatchulidwa ndi mtundu wa imvi wa fracture yomwe imapanga. Chitsulo cha imvi chimagwiritsidwa ntchito popanga nyumba zomwe kuuma kwa chigawocho kuli kofunika kwambiri kuposa mphamvu zake zowonongeka, monga zitsulo zamkati za injini zoyaka moto, nyumba zapampu, matupi a valve, mabokosi amagetsi, zolemera zowerengera ndi zokongoletsera zokongoletsera. Matenthedwe apamwamba a chitsulo cha Grey cast ndi mutu wake nthawi zambiri amagwiritsidwa ntchito popanga zophikira zachitsulo ndi ma disc brake rotor. Zomwe zimapangidwira kuti mupeze graphic microstructure ndi 2.5 mpaka 4.0% carbon ndi 1 mpaka 3% silicon polemera. Graphite amatha kutenga 6 mpaka 10% ya voliyumu yachitsulo chotuwa. Silicon ndi yofunika kupanga chitsulo imvi mosiyana ndi chitsulo choyera, chifukwa silicon ndi graphite stabilizing element mu iron cast, kutanthauza kuti amathandiza alloy kupanga graphite m'malo carbides chitsulo; pa 3% silicon pafupifupi palibe mpweya umene umakhala ndi mankhwala osakaniza ndi chitsulo. graphite amatenga mawonekedwe a mbali zitatu za flake. M'miyeso iwiri, ngati malo opukutidwa adzawonekera pansi pa maikulosikopu, ma graphite flakes amawoneka ngati mizere yabwino. Chitsulo chotuwira chimakhalanso ndi mphamvu yabwino kwambiri yonyowetsa, chifukwa chake chimagwiritsidwa ntchito kwambiri ngati maziko oyika zida zamakina.