Bakin karfe flange ne wani nau'i na farantin sassa, mafi yawa a bututun aiki, flanges ne a biyu-biyu amfani. A cikin aikin bututun bututun, ana amfani da flanges don haɗin bututun bututun. A bututun da ake buƙatar haɗuwa, daban-daban baken karfe flat walda flanges shigar da wani yanki flanges, low matsin lamba bututun za a iya amfani da waya flanges, amfani da walda flanges a kan matsin lamba na 4kg. Ƙara hatimi matsayi tsakanin biyu flanges, sa'an nan kuma ƙarfafa da bolt. Flanges na daban-daban matsin lamba suna da daban-daban kauri da kuma amfani da daban-daban bolts.