I-S31803 uhlelo lokufaka izinombolo oluhlanganisiwe (ama-UNS) lwensimbi yokuqala yensimbi engenacala. Uhlelo olungeyena lwakhiwa amaqembu amaningi okuhweba ngawo-1970s ukunciphisa ukudideka lapho i-alloy efanayo ibizwa ngezinto ezahlukene, futhi okuphambene nalokho. Insimbi ngayinye imelelwa yincwadi elandelwa izinombolo ezinhlanu, lapho incwadi imele uchungechunge lwensimbi, i.e. s ngensimbi engagqwali.
Ukuze izinhlelo zokusebenza ze-Pers Mill ezidinga amamaki aphansi angenawo ukumelana nokwanele. Kususelwa kokuqukethwe kwe-chromium engama-22%, bane-auntenitic ehlanganisiwe: i-fisscitic fickscucture enikeza amandla amakhulu, ukumelana nokugqwala kanye nokusebenza kwezindleko.
Ukucaciswa kwe-UNS S31803 (ASTM F51) kudluliselwe kakhulu yi-UNS S32205 (1.4462, ASTM F60). Lokhu kukhombisa isifiso sabo sokwandisa izakhiwo zokugqwala kwe-alloy, ngenxa yokuthuthukiswa kwenqubo yokwenza insimbi ye-AOD, okuvumela ukulawulwa okunzima kokwakheka. Ngaphezu kwalokho, kuvumela ukuthonya izinga lesengezo le-nitrogen kunokuba nje likhona njengento yangemuva. Ngakho-ke, amamaki aphezulu aphezulu kakhulu afuna ukukhulisa okuqukethwe kwe-chromium (CR), i-molybdenum (mo) ne-nitrogen (n).