Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements4 elements | |||
| Fe | Iron | Bal. | |
| Ni | Nickel | 34 – 37% | |
| Cr | Chromium | 17 – 20% | |
| Si | Silicon | 0.75 – 1.5% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual7 elements | |||
| C | Carbon | ≤ 0.08% | |
| Mn | Manganese | ≤ 2% | |
| Cu | Copper | ≤ 1% | |
| Pb | Lead | ≤ 0.005% | |
| Sn | Tin | ≤ 0.025% | |
| P | Phosphorus | ≤ 0.03% | |
| S | Sulphur | ≤ 0.03% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Round bar | Annealed (minimum annealing temperature 1040 °C) | ≥ 485 (70 ksi) | ≥ 210 (30 ksi) | ≥ 30 | |
| Non-round bar and shapes | Annealed (minimum annealing temperature 1040 °C) | ≥ 485 (70 ksi) | ≥ 210 (30 ksi) | ≥ 25 | |
| Bars and shapes (boiler and pressure-vessel use) | Annealed | ≥ 485 (70 ksi) | ≥ 205 (30 ksi) | ≥ 30 | |
| Bars ≤160 mm (EN 10095, reference grade 1.4886) | +AT (solution annealed) | 500 – 650 | ≥ 270 | ≥ 40 | Rp1.0 ≥ 300 MPa. 1.4886 (X10NiCrSi35-19) is close to N08330 in composition but is not the same grade. |
| Plate, sheet and strip | |||||
| Plate, sheet and strip | Annealed (minimum annealing temperature 1040 °C for N08330) | ≥ 483 (70 ksi) | ≥ 207 (30 ksi) | ≥ 30 | |
| Plate, sheet and strip | Annealed | ≥ 483 (70 ksi) | ≥ 207 (30 ksi) | ≥ 30 | |
| Tube and pipe | |||||
| Seamless pipe and tube | Annealed (minimum annealing temperature 1040 °C) | ≥ 483 (70 ksi) | ≥ 207 (30 ksi) | ≥ 30 | |
| Electric-fusion-welded pipe | Final annealed condition (minimum annealing temperature 1040 °C) | ≥ 483 (70 ksi) | ≥ 207 (30 ksi) | ≥ 30 | |
| Fittings and flanges | |||||
| Fittings (factory-made wrought butt-weld / socket) | 1900 °F [1038 °C], rapid air or water quench | — | — | — | Recommended temperature; tolerance ±15 °C (±25 °F). Tensile properties follow the starting material. No tension test on the finished fitting unless agreed. |
| Fittings (wrought austenitic stainless, butt-weld / socket) | Solution annealed 1900 °F [1038 °C], water quenched or otherwise rapidly cooled | ≥ 485 (70 ksi) | ≥ 205 (30 ksi) | ≥ 30 | Elongation: ≥28% longitudinal, ≥20% transverse. A single temperature is a minimum. All fittings are supplied heat-treated. Elongation ≥30% over a 2 in. (50 mm) gauge length. |
| Several forms | |||||
| Bar, wire, forgings and flash-welded rings (≤203 mm) | Solution heat treated | ≥ 483 (70 ksi) | ≥ 172 (25 ksi) | ≥ 30 | Also specified: Hardness ≤ 95 HRB |
Hardness requirement
Informative only — not a basis for acceptance — 70 – 90 HRB (electric fusion welded pipe, annealed)
⚠ This is not an acceptance criterion.
More detail 5
Hardness values are informative only and are not a basis for acceptance.
A buyer rejecting a lot that reads 92 HRB but passes the tensile test has no standing under the specification.
N08332 in the same table is likewise informative, at 65–88 HRB.
The binding requirements are the tensile ones — annealed N08330 at ≥483 MPa, ≥207 MPa yield and ≥30% elongation — together with the 1900 °F (1040 °C) minimum annealing temperature.
Note also that the grain-size requirement (ASTM No. 5 or coarser) applies to N08332, not N08330: alloy 330 itself carries no grain-size acceptance requirement.
Creep behaviour
Guidance values (MPa) — Mean values of a scatter band. They are neither an acceptance requirement nor a design allowable stress. Figures in parentheses are long-term extrapolations and less reliable than the tested range.
| Temp °C | Creep strength Rp1.0 (1% plastic strain) | Rupture strength Ru | |
|---|---|---|---|
| 10 000 h | 1 000 h | 10 000 h | |
| 600 | 60 | 190 | 130 |
| 700 | 35 | 80 | 55 |
| 800 | 20 | 43 | 26 |
| 900 | 10 | 22 | 13 |
| 1000 | (4) | — | — |
⚠ THIS IS REFERENCE DATA. The table above is for EN 1.4886 X10NiCrSi35-19, not for UNS N08330 itself.
Rp1.0 is the stress producing 1 % plastic elongation and Ru the stress to rupture; at the same temperature and time Rp1.0 is necessarily below Ru. Design deflection-sensitive parts to Rp1.0 and design to fracture with Ru.
Composition, EN 10095 against ASTM: Cr 17.00-20.00 against 17-20 and Ni 33.00-37.00 against 34-37 — the main elements line up. Carbon and silicon do not: EN allows C ≤0.15 and Si 1.00-2.00, whereas ASTM N08330 is C ≤0.08 and Si 0.75-1.50. EN permits nearly twice the carbon, and carbon bears directly on creep strength.
⚠ A common mismatch worth correcting: many cross-reference tables pair the EN name X12NiCrSi35-16 with the material number 1.4886. In EN 10095, X12NiCrSi35-16 is 1.4864 (Cr 15-17) and X10NiCrSi35-19 is 1.4886 (Cr 17-20). On the chromium window it is 1.4886, not 1.4864, that is close to N08330.
1 000 h strength for 1 % elongation: 110 MPa at 600 °C, 60 at 700 °C, 25 at 800 °C and 12 at 900 °C.
⚠ There are no 100 000 h (about eleven-year) values for 1.4886.
⚠ The maximum application temperature in air, Tₐ = 1 100 °C, is an oxidation criterion (defined by scaling loss), not a load-bearing one. N08330 is a classic furnace-component alloy and a classic case of good oxidation resistance with weak load-bearing capacity: at 900 °C and 10 000 h the rupture strength is 13 N/mm².
Where this grade is recommended
Matched in 3 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Furnace internals & fixtures | Furnaces & Vacuum | 900 – 1150 °C | 3 / 12 | 90 |
| Muffles & radiant tubes | Furnaces & Vacuum | 1000 – 1150 °C | 3 / 9 | 89 |
| Quench & carburising fixtures | Furnaces & Vacuum | 950 – 1050 °C | 3 / 8 | 88 |
Designations & equivalents
| W.Nr. (Germany) | 1.4886 |
| EN designation | X10NiCrSi35-19 |
| Trade name(s) | RA330 / Incoloy 330 / Nicrofer 3718 |
| ASTM / AISI | A182 / A240 / A276 / A403 / A479 / B366 / B511 / B535 / B536 / B546 |
| AMS (SAE aerospace) | 5716 |
N08330 and N08332 are not interchangeable — state the UNS number on the order.
More detail 2
The two have almost the same base chemistry, but N08332 requires annealing at 1150 °C or higher and a grain size of ASTM 5 or coarser, and has lower room-temperature strength.
The European 1.4886 (X10NiCrSi35-19) is the usual cross-reference but not an identical grade; check the composition item by item before substituting it.
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
10 specifications. Name the standard and its edition on the order.
For B546 welded pipe the weld composition is by default guaranteed for chromium and nickel only, not for the silicon this grade relies on.
More detail 1
For carburising or similarly severe service, specify the filler metal and a weld-deposit analysis on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is Alloy 330 (RA330) · UNS N08330?
Alloy 330 (RA330) · UNS N08330 — Fe-Ni superalloys. The heat-treat classic — baskets, muffles and radiant tubes; resists carburising and nitriding
What is the maximum service temperature of N08330?
Typically about 1149 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of N08330?
The specified minimum tensile strength is 483 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover N08330?
ASTM B536, ASTM B511/B511M, ASTM B535, ASTM B546, ASTM A240/A240M, ASTM A182/A182M, ASTM A276/A479, ASTM A403/A403M, AMS5716, EN 10095 (reference grade 1.4886)
Where is N08330 typically used?
Furnace internals & fixtures (Furnaces & Vacuum); Muffles & radiant tubes (Furnaces & Vacuum); Quench & carburising fixtures (Furnaces & Vacuum)
In which forms is N08330 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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