An zaɓi ƙarfe mai siffar ƙwallo mai siffar carbon da chromium kuma an yi masa tauri don jure matsin lamba mai tsanani tsakanin abin birgima da zoben ɗaukar nauyi.
Yin amfani da Carbonitriding a kan zoben ciki da na waje tsari ne na taurarewa ga yawancin masu samar da bearings na TPI. Ta hanyar wannan maganin zafi na musamman, taurin kan saman hanyar tsere yana ƙaruwa; wanda ke rage lalacewa daidai gwargwado.
Ana samun ƙarfe mai tsabta sosai a cikin wasu samfuran samfuran bearings na TPI na yau da kullun, don haka ana samun juriya mai ƙarfi. Tunda gajiyar hulɗa galibi tana faruwa ne sakamakon haɗakar ƙarfe mai tauri, bearings a zamanin yau suna buƙatar matakan tsafta na musamman.