Stainless Steel S44700
UNS S44700
S44700 (AL 29-4) is an extremely high-purity 29Cr-4Mo ferritic stainless steel with no intentional nickel addition, supplied as annealed sheet, plate and tube.
Reference datasheet — S44700 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
S44700 tempers and conditions
S44700 is supplied in one standard condition, Annealed. Annealed is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways S44700 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Annealed-Plate | Annealed hot-rolled plate | Supply form |
Annealed-Sheet | Annealed cold-rolled sheet/strip | Supply form |
Annealed-Tube | Annealed welded/seamless tube | Supply form |
What is S44700?
S44700 (AL 29-4) is an extremely high-purity 29Cr-4Mo ferritic stainless steel with no intentional nickel addition, supplied as annealed sheet, plate and tube. It is specified where chloride pitting and stress-corrosion cracking resistance must be maximised in seawater, giving 470 MPa yield, 600 MPa tensile, 27 % elongation and 195 HB. Interstitial pickup during welding causes severe embrittlement, section thickness is limited by low toughness, and service stops at 315 °C. Stabilized S44725 (29-4C type) offers better weld toughness at similar corrosion performance. S44700 has a density of 7.67 g/cm³ (0.277 lb/in³), lighter than 95% of stainless steel grades. It melts at 1,450°C (2,642 °F). S44700 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
What is S44700 used for?
- seawater heat exchangers
- desalination plants
- chemical process equipment
Advantages
- Good corrosion resistance — 88/100, better than 97% of stainless steel grades
Limitations
- Limited service temperature — 315°C (599 °F), worse than 85% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
S44700 properties
Typical room-temperature values for S44700-Annealed; bars are the position among stainless steel grades.
Physical3
S44700 has a density of 7.67 g/cm³ (0.277 lb/in³), lighter than 95% of stainless steel grades. It melts at 1,450°C (2,642 °F).
Mechanical13
S44700 has a yield strength of 470 MPa (68.2 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 74% of stainless steel grades. Elongation at break is 27% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S44700 is rated for continuous service to 315°C (599 °F). It conducts heat at 17 W/m·K (9.82 BTU/hr·ft·°F), better than 71% of stainless steel grades. Thermal expansion is 9.9 µm/m·K (5.5 µin/in·°F).
Electrical3
S44700 conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 97% of stainless steel grades.
Sustainability4
Producing a kilogram of S44700 takes about 62 MJ of energy and emits 4.8 kg of CO₂ — more than 75% of stainless steel grades. Typical recycled content is 25%.
Manufacturability7
S44700's machinability is fair (40/100, better than 72% of stainless steel grades); weldability fair (50/100); formability good (55/100).
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. S44700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with S44700
Is S44700 easy to machine?
Machines like a tough ferritic — rigid setups, sharp positive-rake carbide, moderate speed with heavy feed to avoid work-hardened skin; expect ~40 % of 1212 rating.
Can S44700 be welded?
Autogenous GTAW/PAW with high-purity argon (front and back purge) is preferred; any carbon, nitrogen or oxygen pickup causes severe embrittlement and sensitization — no preheat, low heat input, or use a Ni-base filler.
Can S44700 be formed, bent or molded?
Cold formable in thin gauge with generous bend radii (≥2t) and allowance for higher springback than austenitics; avoid forming heavy sections below ambient temperature.
S44700 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 |
|---|---|---|
| CC+N ≤ 0.025 % | ≤ 0.01 | 0.01 |
| NC+N ≤ 0.025 % | ≤ 0.02 | 0.01 |
| Cr | 28 – 30 | 29 |
| Mo | 3.5 – 4.2 | 4 |
| Niresidual only, not intentionally added | ≤ 0.15 | 0.1 |
| Cu | ≤ 0.15 | 0.05 |
| Mn | ≤ 0.3 | 0.2 |
| Si | ≤ 0.2 | 0.15 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on S44700?
Pickle and passivate per ASTM A967 after hot work or welding; polishes cleanly to bright finishes; do not anodize.
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
Equivalent designations
Standards and trade names that resolve to Stainless Steel S44700 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- AL 29-4
- Also called
- 29-4
How much does S44700 cost?
S44700 is a high-cost stainless steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
S44700 — frequently asked
What is S44700 used for?
S44700 is typically used for seawater heat exchangers, desalination plants and chemical process equipment. In short: 29Cr-4Mo, highest-Cr ferritic; nickel-free chloride SCC resistance; thin-gauge product only.
What is the yield strength of S44700?
S44700 has a typical yield strength of 470 MPa (68.2 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 74% of stainless steel grades.
Is S44700 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machines like a tough ferritic — rigid setups, sharp positive-rake carbide, moderate speed with heavy feed to avoid work-hardened skin; expect ~40 % of 1212 rating.
Can S44700 be welded?
With care — weldability is rated fair (50/100). Autogenous GTAW/PAW with high-purity argon (front and back purge) is preferred; any carbon, nitrogen or oxygen pickup causes severe embrittlement and sensitization — no preheat, low heat input, or use a Ni-base filler.
What surface finishes work on S44700?
Pickle and passivate per ASTM A967 after hot work or welding; polishes cleanly to bright finishes; do not anodize.
Can S44700 be formed, bent or molded?
Cold formable in thin gauge with generous bend radii (≥2t) and allowance for higher springback than austenitics; avoid forming heavy sections below ambient temperature.
What is the maximum service temperature of S44700?
S44700 is rated for continuous use to about 315°C (599 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does S44700 cost?
S44700 is a high-cost stainless steel ($$$$), 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 A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip — ASTM International (2023)
- ASTM A268/A268M — Seamless and Welded Ferritic/Martensitic Stainless Steel Tubing — ASTM International (2022)
- ASTM A731/A731M — Seamless and Welded Ferritic Stainless Steel Pipe — ASTM International (2021)
- AL 29-4 / AL 29-4C Superferritic Stainless Steel Technical Data — ATI (Allegheny Ludlum) (2015)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- UNS S44700 alloy data — SAE/ASTM Unified Numbering System (2020)
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.