Stainless Steel 444
AISI/SAE 444 · UNS S44400 · EN 1.4521, X2CrMoTi18-2 · JIS SUS444 · GB 022Cr18Mo2Ti
444 (S44400, 1.4521, X2CrMoTi18-2) is a titanium/niobium-stabilized 18% Cr ferritic stainless with about 2% molybdenum, giving pitting resistance approaching 316.
Values for the Annealed condition
444 tempers and conditions
444 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault mill annealed (bright/pickled sheet, plate, tube, bar) | Standard supply condition for essentially all 444 product; use for forming, welding and general corrosion service. | 350 | 490 | 30 | 180 HB | — |
cold drawn/cold finished bar and tube | Use where higher strength, tighter tolerance and better machined finish are needed on bar or small tube; ductility and formability drop. | 470 | 570 | 18 | 17 HRC | 2.8 % IACS |
Supply forms, finishes and certifications
Ways 444 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
2B | Cold rolled, annealed, pickled, lightly skin-passed | Surface finish |
BA | BA | Surface finish |
HRAP | HRAP | Surface finish |
What is 444?
444 (S44400, 1.4521, X2CrMoTi18-2) is a titanium/niobium-stabilized 18% Cr ferritic stainless with about 2% molybdenum, giving pitting resistance approaching 316. It is stocked as annealed and 2B/BA sheet, HRAP plate and cold-drawn bar, and is chosen as a nickel-free substitute for 316L in hot water and solar thermal service, with 350 MPa yield, 490 MPa tensile and 30% elongation. Limits are lower stretch formability than austenitics (score 70), machinability around 45, and an 800 °C service ceiling. 316L remains the alternative where deep drawing or higher strength is required. 444 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,425°C (2,597 °F). 444 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 52% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
What is 444 used for?
- Water heater tanks
- Solar absorber panels
- Hot water and potable water piping
- Heat exchanger and condenser tubing
- Food processing equipment
- Coastal architectural trim and cladding
- Chemical storage vessel liners
Advantages
- Conducts heat well — 26 W/m·K (15 BTU/hr·ft·°F), better than 96% of stainless steel grades
- Easy to machine — 45/100, better than 84% of stainless steel grades
- High electrical conductivity — 2.8 % IACS, better than 79% of stainless steel grades
- Forms and bends easily — 70/100, better than 79% of stainless steel grades
Limitations
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 92% of stainless steel grades
444 properties
Typical room-temperature values for 444-Annealed; bars are the position among stainless steel grades.
Physical3
444 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
444 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 52% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
444 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), better than 96% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
444 conducts electricity at 2.8 % IACS, better than 79% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 73% of stainless steel grades.
Sustainability4
Producing a kilogram of 444 takes about 55 MJ of energy and emits 4.2 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability6
444's machinability is fair (45/100, better than 84% of stainless steel grades); weldability good (65/100); formability very good (70/100).
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. 444 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 444
Is 444 easy to machine?
Machines more freely than 316L with lower work hardening — use rigid setups, sharp positive-rake carbide, moderate speed and generous coolant to avoid built-up edge from Ti/Nb carbonitrides.
Can 444 be welded?
Readily GTAW/GMAW/laser welded thanks to Ti+Nb stabilization; keep heat input and interpass temperature low to limit HAZ grain growth, use 316L or matching Nb-stabilized filler (or autogenous on thin gauge), no post-weld anneal needed.
Can 444 be formed, bent or molded?
Good roll forming, bending and deep drawing with low springback and less work hardening than austenitics, but lower n-value means limited stretch forming; avoid tight bends transverse to rolling in heavy gauge.
Manufacturability
The process limits FabDigit applies to 444. Every 444 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better45 / 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 | Better70 / 100 |
|---|---|
| Weldability | Fair65 / 100 |
| Bendable | Yes |
444 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 | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.4 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 17.5 – 19.5 | 18.5 |
| Niresidual only | ≤ 1 | 0.3 |
| Mopitting resistance | 1.75 – 2.5 | 2 |
| N | ≤ 0.04 | 0.02 |
| Ti+NbTi+Nb ≥ 0.20 + 4(C+N); dual stabilization | 0.2 – 0.8 | 0.4 |
| Fe | balance |
What surface finishes work on 444?
Passivates naturally; pickle and passivate after welding to restore the Cr-Mo oxide film, takes 2B/BA and mechanical polishing well, and can be electropolished — no anodizing.
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 444 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S44400
- EN / DIN / Werkstoff-Nr.
- 1.4521X2CrMoTi18-2
- GB (China)
- 022Cr18Mo2Ti
- JIS
- SUS444
How much does 444 cost?
444 is a premium-cost stainless steel ($$$), cheaper 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.
444 — frequently asked
What is 444 used for?
444 is typically used for water heater tanks, solar absorber panels, hot water and potable water piping, heat exchanger and condenser tubing, food processing equipment and coastal architectural trim and cladding. In short: super-ferritic chemical stainless.
What is the yield strength of 444?
444 has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 52% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is 444 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 84% of stainless steel grades). Machines more freely than 316L with lower work hardening — use rigid setups, sharp positive-rake carbide, moderate speed and generous coolant to avoid built-up edge from Ti/Nb carbonitrides.
Can 444 be welded?
Yes — weldability is rated good (65/100). Readily GTAW/GMAW/laser welded thanks to Ti+Nb stabilization; keep heat input and interpass temperature low to limit HAZ grain growth, use 316L or matching Nb-stabilized filler (or autogenous on thin gauge), no post-weld anneal needed.
What surface finishes work on 444?
Passivates naturally; pickle and passivate after welding to restore the Cr-Mo oxide film, takes 2B/BA and mechanical polishing well, and can be electropolished — no anodizing.
Can 444 be formed, bent or molded?
Good roll forming, bending and deep drawing with low springback and less work hardening than austenitics, but lower n-value means limited stretch forming; avoid tight bends transverse to rolling in heavy gauge.
What is the maximum service temperature of 444?
444 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 444 cost?
444 is a premium-cost stainless steel ($$$), cheaper 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 444?
Yes — 444 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 A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip (S44400) — ASTM International (2023)
- EN 10088-1/-2 — Stainless steels, list of grades and technical delivery conditions (1.4521) — CEN (2014)
- GB/T 3280 — (00Cr18Mo2) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Ferritic stainless 4521 / 444 data sheet — Outokumpu (2023)
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.