Stainless Steel S33425
UNS S33425
S33425 is a high-nickel, 330-family heat-resistant austenitic stainless with strong resistance to carburization, oxidation and thermal cycling above 1000 °C.
Reference datasheet — S33425 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Annealed condition
S33425 tempers and conditions
S33425 is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault Annealed (solution annealed, 1050–1150 °C, rapid cool) | Standard stocked condition for plate, sheet, bar, pipe and fittings — maximum ductility and best cyclic-oxidation life. | 275 | 585 | 45 | 150 HB | — |
As-welded deposit | Joint condition for fabricated furnace hardware; use when a full post-weld solution anneal is impractical. | 300 | 560 | 32 | 170 HB | 1.7 % IACS |
Cold drawn | Small-diameter bar and fasteners where straightness, tolerance and higher room-temperature strength are wanted. | 500 | 720 | 25 | 17 HRC | 1.7 % IACS |
Cold worked 1/4-hard | Lightly temper-rolled strip/wire for springy clips, mesh and formed hardware; cold work is lost on first high-temperature exposure. | 590 | 790 | 20 | 22 HRC | 1.7 % IACS |
Supply forms, finishes and certifications
Ways S33425 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
BA-TUBE | Bright annealed tube / pipe | Supply form |
CRA-2B | CRA 2B | Surface finish |
HRAP | Hot rolled, annealed and pickled | Surface finish |
What is S33425?
S33425 is a high-nickel, 330-family heat-resistant austenitic stainless with strong resistance to carburization, oxidation and thermal cycling above 1000 °C. Annealed material gives 275 MPa yield, 585 MPa tensile, 45 % elongation and about 150 HB (80 HRB), with a maximum service temperature near 1150 °C; it is available as HRAP plate, CRA-2B and bright-annealed tube, cold-drawn bar and 1/4 hard cold-worked product. Low thermal conductivity and a high work-hardening rate make it slow to machine (formability score 65), and it is a higher-cost specialty melt; 310S is the cheaper option where carburization is not the controlling mechanism. S33425 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). S33425 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
What is S33425 used for?
- furnace fixtures
- carburizing baskets
- heat-treatment equipment
Advantages
- High service temperature — 1,150°C (2,102 °F), better than 99% of stainless steel grades
- Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades
Limitations
- High embodied carbon — 6.8 kg CO₂/kg, worse than 95% 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
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Low strength — 275 MPa (39.9 ksi), worse than 77% of stainless steel grades
S33425 properties
Typical room-temperature values for S33425-Annealed; bars are the position among stainless steel grades.
Physical3
S33425 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
S33425 has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
S33425 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
S33425 conducts electricity at 1.7 % IACS, worse than 93% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of S33425 takes about 90 MJ of energy and emits 6.8 kg of CO₂ — more than 94% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
S33425's machinability is poor (30/100, worse than 70% of stainless steel grades); weldability good (68/100); 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. S33425 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S33425
Is S33425 easy to machine?
Treat as a high-nickel austenitic: rigid setup, positive-rake carbide, 20–35 m/min in turning, heavy feed, flood coolant and no dwelling — it work-hardens fast and its low conductivity concentrates heat at the edge.
Can S33425 be welded?
GTAW/GMAW/SMAW with matching 330 filler (or ERNiCr-3/A-alloy fillers for higher hot-crack safety); no preheat, low heat input, interpass below ~150 °C, and full solution anneal if the part will see 650–900 °C service.
Can S33425 be formed, bent or molded?
Formable cold in the annealed state but with a high work-hardening rate and marked springback — allow extra bend radius, use interstage anneals for deep draws; hot work at 1100–1200 °C and finish above ~950 °C.
S33425 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 |
|---|---|---|
| Clow carbon for weldability; heat-resistant variants may run to 0.10 | ≤ 0.08 | 0.05 |
| Sikey addition — forms adherent Si-rich sub-scale, boosts carburization resistance | 0.75 – 1.5 | 1.2 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.03 | 0.02 |
| Skept low — sulphur harms hot ductility of high-Ni alloys | ≤ 0.03 | 0.01 |
| Cr | 17 – 20 | 18.5 |
| Nistabilizes austenite and resists carbon/nitrogen pick-up | 33 – 37 | 35 |
| N | ≤ 0.1 | 0.03 |
| Febalance, ≈43–46 % | balance |
What surface finishes work on S33425?
Pickle and passivate after hot work or welding to remove the tenacious Si-rich scale; brushed/polished or electropolished finishes are achievable, and aluminizing or Cr-diffusion coatings can extend life in aggressive carburizing service. 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).
Passivation
Organic Coating
Thermal Spray
How much does S33425 cost?
S33425 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
S33425 — frequently asked
What is S33425 used for?
S33425 is typically used for furnace fixtures, carburizing baskets and heat-treatment equipment. In short: carburization-resistant 330 type; 1150 °C service limit; furnace-fixture workhorse.
What is the yield strength of S33425?
S33425 has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 585 MPa (84.8 ksi) — weaker than 77% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S33425 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 70% of stainless steel grades). Treat as a high-nickel austenitic: rigid setup, positive-rake carbide, 20–35 m/min in turning, heavy feed, flood coolant and no dwelling — it work-hardens fast and its low conductivity concentrates heat at the edge.
Can S33425 be welded?
Yes — weldability is rated good (68/100). GTAW/GMAW/SMAW with matching 330 filler (or ERNiCr-3/A-alloy fillers for higher hot-crack safety); no preheat, low heat input, interpass below ~150 °C, and full solution anneal if the part will see 650–900 °C service.
What surface finishes work on S33425?
Pickle and passivate after hot work or welding to remove the tenacious Si-rich scale; brushed/polished or electropolished finishes are achievable, and aluminizing or Cr-diffusion coatings can extend life in aggressive carburizing service. Not anodizable.
Can S33425 be formed, bent or molded?
Formable cold in the annealed state but with a high work-hardening rate and marked springback — allow extra bend radius, use interstage anneals for deep draws; hot work at 1100–1200 °C and finish above ~950 °C.
What is the maximum service temperature of S33425?
S33425 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.
What is the difference between S33425 Annealed and S33425-CD?
Annealed is the default condition — standard stocked condition for plate, sheet, bar, pipe and fittings — maximum ductility and best cyclic-oxidation life. CD: small-diameter bar and fasteners where straightness, tolerance and higher room-temperature strength are wanted. Yield strength is 275 MPa in Annealed versus 500 MPa in CD.
How much does S33425 cost?
S33425 is a high-cost stainless steel ($$$$), pricier than about 78% 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.
Sources
- ASTM B511 / B535 / B536 / B546 / B710 — Alloy N08330 bar, pipe, sheet, tube and wire — ASTM International (2019)
- ASTM A240/A480 — heat-resisting Cr-Ni plate, sheet and strip — ASTM International (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (heat-resistant austenitics) — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (high-temperature corrosion of Fe-Ni-Cr alloys) — ASM International (2005)
- Alloy 330 / RA330 heat-resistant alloy datasheet (typical physical and mechanical properties) — specialty alloy producer (2022)
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.