Mapulogalamu
▪ Mpira woyeretsera mozungulira: ndi mtundu wa makina opopera mankhwala ozungulira, omwe amagwiritsa ntchito zotsukira kupopera mwamphamvu ndi kuyeretsa mkati mwa thanki.Ndi imodzi yomwe imakhala yabwino m'malo mwa mpira woyeretsera wokhazikika chifukwa ukhoza kugwiritsidwa ntchito pansi pa mphamvu yochepa yokhala ndi zotsukira zochepa.Makina opoperapo a rotary amagwiritsa ntchito mipira iwiri, kotero ndiyoyenera kugwiritsa ntchito ukhondo ndi mafakitale, kuphatikiza thanki, riyakitala, chotengera etc.
▪ Mpira woyeretsera wokhazikika: ndi mtundu wa mpira wosasunthika wa tanki yosungiramo.Mpira wopopera wokhazikika umagwiritsidwa ntchito kuyeretsa ndi zofunikira zochepa.