Stainless Steel S44330
UNS S44330
S44330 is a Ti/Nb-stabilized 18Cr ferritic stainless with a modest molybdenum addition that lifts pitting resistance above plain Type 439.
Reference datasheet — S44330 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 ANN condition
S44330 tempers and conditions
S44330 is supplied in 4 conditions, soft to hard. ANN 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 |
|---|---|---|---|---|---|---|
As-welded deposit | Reference condition for stabilized-grade joints: no sensitization, but coarse ferrite grain lowers ductility and toughness locally. | 300 | 470 | 18 | 170 HB | 2.9 % IACS |
ANNDefault Annealed | Standard as-supplied condition for all forming, stamping and welding work. | 310 | 480 | 30 | 160 HB | 2.9 % IACS |
Temper rolled / skin passed | Use for flatter strip and slightly higher yield where only mild bending is required. | 420 | 540 | 20 | 175 HB | 2.9 % IACS |
1/4 Hard | For springy clips and flat parts needing higher yield with limited bending. | 520 | 620 | 12 | 15 HRC | 2.9 % IACS |
Supply forms, finishes and certifications
Ways S44330 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Tube-Ann | Welded tube, annealed | Supply form |
2B | Cold rolled, annealed, pickled, lightly skin-passed bright finish | Surface finish |
BA | BA | Surface finish |
HRAP | No.1 / HRAP | Surface finish |
What is S44330?
S44330 is a Ti/Nb-stabilized 18Cr ferritic stainless with a modest molybdenum addition that lifts pitting resistance above plain Type 439. It is chosen for mildly corrosive exhaust and appliance service and is supplied as annealed, 2B, BA and HRAP sheet, 1/4-hard cold-worked strip and annealed welded tube; annealed properties are 310 MPa yield, 480 MPa tensile, 30 % elongation and about 160 HB (80 HRB). Maximum service temperature is 870 °C, but ferritic toughness limits heavy sections and chloride resistance stays below 316L — step up to S44401 (444) or S44625 when pitting drives the design. S44330 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F). S44330 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is S44330 used for?
- exhaust components
- appliance trim
- hot-water tank liners
Advantages
- Easy to machine — 55/100, better than 94% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
- Forms and bends easily — 72/100, better than 84% of stainless steel grades
- High service temperature — 870°C (1,598 °F), better than 83% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 85% of stainless steel grades
- Needs corrosion protection — 52/100, worse than 76% of stainless steel grades
S44330 properties
Typical room-temperature values for S44330-ANN; bars are the position among stainless steel grades.
Physical3
S44330 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
S44330 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 63% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S44330 is rated for continuous service to 870°C (1,598 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
S44330 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 76% of stainless steel grades.
Sustainability4
Producing a kilogram of S44330 takes about 50 MJ of energy and emits 3.8 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
S44330's machinability is good (55/100, better than 94% of stainless steel grades); weldability very good (78/100); formability very good (72/100).
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. S44330 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S44330
Is S44330 easy to machine?
Machines more freely than 304 (lower work hardening) but chips are stringy — use sharp positive-rake carbide, rigid setup, generous coolant and moderate speeds.
Can S44330 be welded?
Readily welded by GTAW/GMAW/laser/resistance without post-weld annealing thanks to Ti+Nb stabilization; keep heat input low to limit HAZ grain coarsening, use 439/430Nb or 316L filler and inert shielding (no CO₂-rich gas).
Can S44330 be formed, bent or molded?
Good deep-drawability with low springback and n-value lower than austenitic grades; watch for ridging/roping in the rolling direction on stretched panels and allow generous bend radii on heavier gauges.
S44330 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 stabilization and toughness | ≤ 0.03 | 0.02 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 1 | 0.4 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.03 | 0.01 |
| Cr | 17 – 19.5 | 18 |
| Niresidual | ≤ 0.5 | 0.25 |
| Mopitting resistance addition vs 439 | 0.3 – 0.7 | 0.5 |
| N | ≤ 0.03 | 0.02 |
| Tistabilizer | 0.1 – 0.6 | 0.2 |
| Nbstabilizer, raises creep strength; Ti+Nb ≥ 0.20 + 4(C+N) | 0.3 – 0.8 | 0.45 |
| Fe | balance |
What surface finishes work on S44330?
Passivate or electropolish after fabrication; accepts brushed, 2B, BA and PVD-coloured finishes — not anodizable, and heat tint from welding must be pickled or blasted off to restore corrosion resistance.
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 S44330 cost?
S44330 is a standard-cost stainless steel ($$), cheaper than about 71% 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.
S44330 — frequently asked
What is S44330 used for?
S44330 is typically used for exhaust components, appliance trim and hot-water tank liners. In short: stabilized 439 with Mo; weldable without post-weld anneal; 870 °C exhaust service.
What is the yield strength of S44330?
S44330 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 480 MPa (69.6 ksi) — weaker than 63% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is S44330 easy to machine?
Reasonably — machinability is rated good (55/100, better than 94% of stainless steel grades). Machines more freely than 304 (lower work hardening) but chips are stringy — use sharp positive-rake carbide, rigid setup, generous coolant and moderate speeds.
Can S44330 be welded?
Yes — weldability is rated very good (78/100). Readily welded by GTAW/GMAW/laser/resistance without post-weld annealing thanks to Ti+Nb stabilization; keep heat input low to limit HAZ grain coarsening, use 439/430Nb or 316L filler and inert shielding (no CO₂-rich gas).
What surface finishes work on S44330?
Passivate or electropolish after fabrication; accepts brushed, 2B, BA and PVD-coloured finishes — not anodizable, and heat tint from welding must be pickled or blasted off to restore corrosion resistance.
Can S44330 be formed, bent or molded?
Good deep-drawability with low springback and n-value lower than austenitic grades; watch for ridging/roping in the rolling direction on stretched panels and allow generous bend radii on heavier gauges.
What is the maximum service temperature of S44330?
S44330 is rated for continuous use to about 870°C (1,598 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S44330-ANN and S44330-TR?
ANN is the default condition — standard as-supplied condition for all forming, stamping and welding work. TR: use for flatter strip and slightly higher yield where only mild bending is required. Yield strength is 310 MPa in ANN versus 420 MPa in TR.
How much does S44330 cost?
S44330 is a standard-cost stainless steel ($$), cheaper than about 71% 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 A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip — ASTM International (2023)
- ASTM A268/A268M — Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing — ASTM International (2022)
- SAE J405 — Chemical Compositions of SAE Wrought Stainless Steels — SAE International (2013)
- 18 Cr-Cb (stabilized 18% Cr ferritic) stainless steel data sheet — AK Steel / Cleveland-Cliffs (2021)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — 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.