Na'urar hoop na ƙarfe, wanda kuma aka sani da mashin ɗin, na'ura ce ta gyare-gyare da yankan lokaci guda. Rarraba zuwa 3-axis, 5-axis, 7-axis, 9-axis da sauran samfura. Wannan inji ya dace da kauri na 0.2-2.0mm (gilashin galvanized, sanyi-birgima, takardar da aka yi birgima), faɗin albarkatun ƙasa ≤ 150mm, da diamita na 30-300mm. An haɗe shi da na'ura mai juriya don samar da zoben karfe na hydraulic da samar da layin walda.
Wannan na'ura tana ɗaukar cikakken tuƙi na na'ura mai aiki da karfin ruwa, kuma ana daidaita wayoyi, ana murƙushe su, kuma an yanke su ta hanyar ruwa don zama samfura; Akwatin sarrafawa yana sanye da cikakkun ayyuka kamar ciyarwa da sauri, yankan, atomatik, manual, da dai sauransu, kuma yana da sauƙin aiki. Kuma diamita da tsawon na sarrafa workpiece za a iya kafa sabani. Ana amfani da fa'ida ga nau'ikan coils na waya daban-daban, semicircles, da baka na madauwari a kowane kusurwa (kusurwar maida hankali). An kafa waya a cikin tafi ɗaya kuma ana tafiyar da ita ta servo Motors don tabbatar da ƙananan kurakuran samfur da madaidaici.