M karfe mafi dacewa an yi shi ne da carbon ko ƙarfe, bayanan martaba, zuwa wani tsari, ga wani tsari wanda zai iya yin aiki (canza shugabanci ko ƙima) a cikin tsarin bututun ruwa. Yawancin waɗannan abubuwan fitowar ta haɗa da gwiwar karfe (45 ko 90 na lanƙwasa), Tee, Resolacere, Gicccentric Rage, giciye, iyakoki, flanges da sauransu