Designation Cross-Reference

NA 21 — ASTM Equivalent

Holding a datasheet that specifies NA 21 (BS)? The valve-grade equivalent, its properties, and certified supply of the matching ASTM grade.

What is the ASTM equivalent of NA 21?

NA 21 is a BS designation corresponding to ASTM B574 / UNS N10276 (Hastelloy C-276) for industrial valve service. The full grade data is below - equivalence is by nominal chemistry and mechanical class, so confirm composition and heat-treat condition against the governing standard before substituting in critical service.

B574 / UNS N10276

Nickel Alloys

Hastelloy C-276 - both form.

Service temperature-196°C to +371°C

Nominal compositionNi ≥ 57% (bal.), Mo 15–17%, Cr 14.5–16.5%, W 3–4.5%, Fe 4–7%, Co ≤ 2.5%, C ≤ 0.01%, Mn ≤ 1%, Si ≤ 0.08%. UNS N10276.

Typical service: Hydrochloric acid (all concentrations and temperatures); Wet chlorine gas and sodium hypochlorite; Sulphuric acid at intermediate concentrations

Also designated:N10276 [UNS]2.4819 [DIN / EN]NiMo16Cr15W [DIN / EN]NW-0276 [ISO]NA 21 [BS]

Reviewed by Materials Engineering, Vajra Industrial SolutionsDiscipline: Valve Metallurgy & Materials SelectionLast reviewed: 20 June 2026

Connected Engineering

Materials

Hastelloy C-276

Need valves in NA 21 / its ASTM equivalent?

We supply B574 / UNS N10276 valves - the NA 21 equivalent - with EN 10204 3.1 material certification. Share the datasheet for a 24-hour quote.

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Engineering references

B574 / UNS N10276 full grade pageHastelloy C-276 Equivalence MatrixAll 43 grades across 7 systems Designation lookup directoryEvery foreign designation indexed