Cast iron manhole maida hankali ne zuwa kashi ductile baƙin ƙarfe manhole murfi da kuma launin toka manhole cover, kullum magana, guda nauyi na ductile baƙin ƙarfe manhole maida hankali fiye da launin toka manhole murfin matsa lamba juriya.Abubuwan da aka yi amfani da su don murfin manhole baƙin ƙarfe gabaɗaya shine HT200, kuma kayan da ake amfani da su don murfin manhole na ductile gabaɗaya shine QT500-7.

Halayen murfin tawada na spheroidal:

Kyakkyawan tauri.Ƙimar tasiri tana kama da na matsakaicin ƙarfe na carbon kuma fiye da sau 10 na baƙin ƙarfe.

Juriya mai ƙarfi mai ƙarfi.Gwajin lalatawar ruwa, kwanaki 90 na lalata shine bututun karfe 1/40 kawai, bututun ƙarfe 1/10 ne.Rayuwar sabis shine sau 2 na bututun ƙarfe mai launin toka da kuma sau 5 na bututun ƙarfe na yau da kullun.

Kyakkyawan filastik.Tsawaitawa≥7%, kama da high carbon karfe abu, yayin da launin toka karfe abu elongation ne sifili.

Babban ƙarfi.Ƙarfin ƙarfi ob≥420MPa, samar da ƙarfi os≥300MPa, kuma low carbon karfe ne iri daya, shi ne sau uku na launin toka abu.

Aikace-aikace: titin birni, babbar hanya, sadarwa, wutar lantarki, ruwan famfo, al'umma, makaranta da sauran wuraren shakatawa.