Alloy 330 & Incoloy DS
Aurico Alloys LLP supplies both heat-resisting iron-nickel-chromium-silicon grades for industrial furnace muffles, heat-treating baskets, radiant tubes and petrochemical heaters — carburization resistance well beyond stainless 310.
Two grades, similar but not interchangeable
These alloys are close cousins and are often quoted against each other, but their chemistries differ enough to matter on a mill certificate. Alloy 330 (Rolled Alloys' RA330®) is the ASTM grade; INCOLOY alloy DS is Special Metals' higher-silicon variant, written to a British standard rather than an ASTM one. The extra silicon is what gives DS its resistance to “green rot” in cyclically reducing atmospheres.
| Alloy 330 / RA330® | INCOLOY® alloy DS | |
|---|---|---|
| UNS | N08330 | — |
| W. Nr. | 1.4886 | 1.4862 |
| Specification | ASTM B536 / B511 / B535 | B.S. 3073 NA17 |
| Chromium % | 18.0–20.0 | 17.0–19.0 |
| Nickel % | 34.0–37.0 | 34.5–41.0 (Ni + Co) |
| Silicon % | 1.0–1.5 | 1.9–2.6 |
| Manganese % | 2.0 max | 0.8–1.5 |
| Carbon % | 0.04–0.08 | 0.10 max |
| Density g/cm³ | 7.94 | 7.86 |
| Melting range °C | 1343–1393 | 1330–1400 |
Limits per the Rolled Alloys RA330 sheet and the Special Metals INCOLOY alloy DS bulletin. Registers commonly list Incoloy DS against N08330 as well, but its silicon band sits above the ASTM grade's — so quote the standard, not just the trade name, when the atmosphere or the certificate matters. A third grade sometimes confused with these, 1.4864 (X12NiCrSi35-16), is lower again at 15–17% chromium.
Available Forms
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | N08330 |
| Werkstoff / EN number | 1.4886 |
| Density | 7.94 g/cm3 |
| Melting range | 1343-1393 °C |
| Specific heat (100 °F) | 0.117 Btu/lb·°F (no SI value published) |
| Thermal conductivity (75 °F) | 7.2 Btu·ft/ft²·hr·°F (no SI value published) |
| Electrical resistivity (75 °F) | 616 ohm·circ mil/ft (no SI value published) |
| Coefficient of expansion (70-200 °F) | 8.3 µin/in·°F (no SI value published) |
| Magnetic permeability (annealed at H=2810 oersted) | 1.009 |
Identifiers and physical constants for Incoloy DS. A dash means no such designation is published for this grade.
Specifications by Product Form
Incoloy DS (N08330) is supplied to a different standard in each form. Quote the one that matches the product you are ordering.
| Product form | Specification |
|---|---|
| Plate, sheet and strip | ASTM B536 |
| Rod and bar | ASTM B511 / B512 |
| Pipe and tube | ASTM B535 / B546 / B710 / B739 |
| Fittings | ASTM B366 |
Aurico Alloys LLP supplies Alloy 330 and Incoloy DS across all the forms above, with material test certificates (EN 10204 3.1) and export-ready packaging from Mumbai, India. Contact us for stock availability and pricing.