Standard Specification for Niobium and Niobium Alloy Ingots1
This fashionable is issued under the fixed designation b 391; the wide variety immediately following the designation shows the year of original adoption or, within the case of revision, the 12 months of ultimate revision. A range of in parentheses shows the yr of last reapproval. A superscript epsilon (e) shows an article alternate since the remaining revision or reapproval.
Click below to get ASTM B 391 – 03 International standard
You can also get ASTM B 390 – 92 International standard