Stainless Steel 330
AISI/SAE 330 · UNS N08330 · ASTM A240 Type 330 · EN 1.4886 · also RA330
330 (UNS N08330, RA330, 1.4886) is a 35Ni–19Cr–1.2Si iron–nickel–chromium austenitic heat-resisting alloy whose high silicon content gives oxidation, carburisation and thermal-shock resistance above 1100 °C.
Values for the Solution Annealed condition
330 tempers and conditions
330 is supplied in 5 conditions, soft to hard. Solution Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
mill annealed (soft) sheet, strip and bar | General soft annealed stock for forming and deep-drawn furnace parts where maximum formability is wanted. | 250 | 565 | 45 | 145 HB | 1.7 % IACS |
Solution AnnealedDefault 1065–1150 °C solution anneal, rapid cool | Standard supply condition for sheet, plate, pipe and bar — maximum ductility and best high-temperature oxidation/carburisation performance. | 270 | 585 | 43 | 150 HB | — |
hot rolled/forged bar and plate, annealed after hot work | Economical heavy bar, forgings and thick plate for furnace fixtures and retorts where surface finish and tight tolerance are not critical. | 290 | 600 | 40 | 160 HB | 1.7 % IACS |
weld metal / weldment with matching RA330-04 type filler | Property basis for weldments and weld overlays; matching high-carbon/columbium modified filler is used to avoid hot cracking and to keep creep strength. | 330 | 560 | 28 | 175 HB | 1.7 % IACS |
cold drawn/cold finished bar and wire | Choose for higher room-temperature strength, straightness and good surface on small-diameter bar and wire; ductility and high-temperature stability are reduced (recrystallises in service). | 480 | 700 | 25 | 200 HB | — |
What is 330?
330 (UNS N08330, RA330, 1.4886) is a 35Ni–19Cr–1.2Si iron–nickel–chromium austenitic heat-resisting alloy whose high silicon content gives oxidation, carburisation and thermal-shock resistance above 1100 °C. Plate, sheet, bar and fabricated sections are used for furnace trays and radiant tubes, annealing covers, burner sleeves and cement or petrochemical furnace internals. Sulfur-bearing and reducing sulfidising atmospheres attack it, and its room-temperature and creep strengths are below wrought high-nickel alloys. Work hardening is rapid, machinability is moderate, and welding needs matching RA330-04 filler to avoid hot cracking; 310 is the lower-nickel alternative. 330 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,370°C (2,498 °F). 330 has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 79% of stainless steel grades. Elongation at break is 43% and the elastic modulus is 196 GPa (28.4 Msi).
What is 330 used for?
- Heat treating fixtures and trays
- Furnace muffles and retorts
- Radiant tubes
- Annealing covers
- Burner sleeves
- Cement kiln internals
- Petrochemical furnace hardware
Advantages
- High service temperature — 1,150°C (2,102 °F), better than 99% of stainless steel grades
Limitations
- High embodied carbon — 7.5 kg CO₂/kg, worse than 97% of stainless steel grades
- Low electrical conductivity — 1.7 % IACS, worse than 93% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades
- Low strength — 270 MPa (39.2 ksi), worse than 79% of stainless steel grades
330 properties
Typical room-temperature values for 330-Solution Annealed; bars are the position among stainless steel grades.
Physical3
330 has a density of 7.94 g/cm³ (0.287 lb/in³), heavier than 78% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical13
330 has a yield strength of 270 MPa (39.2 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 79% of stainless steel grades. Elongation at break is 43% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
330 is rated for continuous service to 1,150°C (2,102 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades. Thermal expansion is 14.4 µm/m·K (8 µin/in·°F).
Electrical3
330 conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 330 takes about 95 MJ of energy and emits 7.5 kg of CO₂ — more than 96% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
330's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability good (62/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 330 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 330
Is 330 easy to machine?
Machine like a nickel alloy: rigid setup, positive rake carbide, heavy depth of cut, low speed (≈15–25 m/min HSS, 40–70 m/min carbide), continuous feed and flood coolant to avoid work-hardened glaze.
Can 330 be welded?
GTAW/GMAW/SMAW with matching RA330-04 (or 330-type) filler; no preheat, keep interpass low, low heat input and clean joints to limit hot cracking; avoid autogenous welds on heavy sections.
Can 330 be formed, bent or molded?
Forms cold with good ductility but high work-hardening — allow extra press force, generous radii, and intermediate anneals at 1065–1150 °C for severe draws; hot works at 1100–1230 °C.
Manufacturability
The process limits FabDigit applies to 330. Every 330 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair32 / 100 |
|---|---|
| ISO material group | M.1 |
| Cutting speed (rough / finish) | 150 / 180 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better65 / 100 |
|---|---|
| Weldability | Better62 / 100 |
| Bendable | Yes |
330 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ni | 34 – 37 | 35.5 |
| Cr | 17 – 20 | 18.5 |
| Sihigh Si gives the oxidation/carburisation resistance | 0.75 – 1.5 | 1.15 |
| Mn | ≤ 2 | 1.5 |
| C | ≤ 0.08 | 0.05 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Pb | ≤ 0.01 | |
| Sn | ≤ 0.03 | |
| Cusome specifications only | ≤ 1 | |
| Febalance, nominally ~43 % | balance |
What surface finishes work on 330?
Pickle/passivate or grit blast plus pickling to remove the tenacious Si-rich oxide before service or brazing; takes a fair mechanical polish, not anodizable.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 330 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N08330
- ASTM
- A240 Type 330
- EN / DIN / Werkstoff-Nr.
- 1.4886
- Trade names
- RA330
How much does 330 cost?
330 is a specialty-cost stainless steel ($$$$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
330 — frequently asked
What is 330 used for?
330 is typically used for heat treating fixtures and trays, furnace muffles and retorts, radiant tubes, annealing covers, burner sleeves and cement kiln internals. In short: ultimate heat resistance.
What is the yield strength of 330?
330 has a typical yield strength of 270 MPa (39.2 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 79% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 330 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Machine like a nickel alloy: rigid setup, positive rake carbide, heavy depth of cut, low speed (≈15–25 m/min HSS, 40–70 m/min carbide), continuous feed and flood coolant to avoid work-hardened glaze.
Can 330 be welded?
Yes — weldability is rated good (62/100). GTAW/GMAW/SMAW with matching RA330-04 (or 330-type) filler; no preheat, keep interpass low, low heat input and clean joints to limit hot cracking; avoid autogenous welds on heavy sections.
What surface finishes work on 330?
Pickle/passivate or grit blast plus pickling to remove the tenacious Si-rich oxide before service or brazing; takes a fair mechanical polish, not anodizable.
Can 330 be formed, bent or molded?
Forms cold with good ductility but high work-hardening — allow extra press force, generous radii, and intermediate anneals at 1065–1150 °C for severe draws; hot works at 1100–1230 °C.
What is the maximum service temperature of 330?
330 is rated for continuous use to about 1,150°C (2,102 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 330 cost?
330 is a specialty-cost stainless steel ($$$$$), pricier than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 330?
Yes — 330 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B536 — Ni-Fe-Cr-Si Alloy Plate, Sheet and Strip (UNS N08330) — ASTM (2019)
- ASTM B511 / B512 / B535 / B546 / B710 — N08330 bar, castings, pipe, tube — ASTM (2019)
- RA330 Alloy Data Sheet — Rolled Alloys (2022)
- ASM Handbook Vol. 1 — Heat-Resistant Alloys; Vol. 13B — Corrosion — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.