ASTM A959:2011 409: Ferritic stainless steel type 409 (UNS S40900) with the composition limits of ASTM A959-11. Carbon up to 0.08% and chromium 10.5-11.7%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Cr
Mn
Ni
P
S
Si
<=0.08
10.5-11.7
<=1.00
<=0.50
<=0.045
<=0.030
<=1.00
More data from ASTM A959:2011
From the standard
Other composition limitsfrom Table 1 and its footnotes
UNS number
S40900
Metallurgical class
Ferritic grade: body-centered cubic, little or no tempered martensite, hardenable only slightly by cold working
Type
409 (designation originally assigned by the American Iron and Steel Institute)
Values
Maximum unless a range or minimum is shown; where two limits are shown for the same element in one grade the more stringent applies
Other elements (as printed)
Ti 6xC-0.75
These are the recommended composition limits of the A959 guide, intended for adoption by standards for stainless steel products; they are not a product specification.
Source: ASTM A959:2011, Table 1 and its footnotes
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