Masu dumama na'urorin dumama iska a buɗe su ne masu dumama iska waɗanda ke fallasa matsakaicin yankin saman abin dumama kai tsaye ga iskar iska. Zaɓar na'urorin haɗawa, girma, da ma'aunin waya an zaɓi su da dabara don ƙirƙirar mafita ta musamman bisa ga buƙatun musamman na aikace-aikacen. Ka'idojin aikace-aikacen asali da za a yi la'akari da su sun haɗa da zafin jiki, iskar iska, matsin lamba na iska, muhalli, saurin gudu, mitar keke, sararin zahiri, wutar lantarki da ake da ita, da tsawon lokacin hita.

FA'IDOJI
Shigarwa mai sauƙi
Dogo sosai – ƙafa 40 ko fiye
Mai sassauƙa sosai
An sanye shi da sandar tallafi mai ci gaba wanda ke tabbatar da tauri mai kyau
Dogon tsawon rai na sabis
Rarraba zafi iri ɗaya

Shawarwari

Don amfani a cikin yanayi mai danshi, muna ba da shawarar abubuwan NiCr 80 (mataki na A) na zaɓi.
Sun ƙunshi kashi 80% na nickel da kashi 20% na chrome (ba ya ƙunshe da ƙarfe).
Wannan zai ba da damar matsakaicin zafin aiki na 2,100o F (1,150o C) da kuma shigarwa inda za a iya samun danshi a cikin bututun iska.