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Stainless Steel 254 SMO · supply condition

Stainless Steel 254 SMO-CD

Properties of the CD condition, compared with the other 254 SMO tempers.

Pick for higher-strength fasteners, shafts and pump parts where tight tolerance and bright finish are needed.

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Request a quote in 254 SMO-CD254 SMO overview

What is 254 SMO-CD?

254 SMO-CD is 254 SMO supplied in the CD condition — pick for higher-strength fasteners, shafts and pump parts where tight tolerance and bright finish are needed. 254 SMO-CD has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 195 GPa (28.3 Msi). 254 SMO-CD has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F). Solution Annealed is the default condition FabDigit quotes; CD is available on request or by drawing note.

Advantages

  • Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
  • Good corrosion resistance — 84/100, better than 91% of stainless steel grades
  • Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
  • High strength — 620 MPa (89.9 ksi), better than 88% of stainless steel grades

Limitations

  • High embodied carbon — 6.5 kg CO₂/kg, worse than 92% of stainless steel grades
  • Difficult to machine — 25/100, worse than 88% of stainless steel grades
  • Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
  • Low electrical conductivity — 2 % IACS, worse than 78% of stainless steel grades

254 SMO-CD properties

Typical room-temperature values for 254 SMO-CD — 10 properties are specific to this condition; the rest are grade-level values shared by every 254 SMO temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.

Physical3

254 SMO-CD has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,325°C (2,417 °F).

Density8 g/cm³0.29 lb/in³
Melting Point (Solidus)1,325°C2,417 °F
Liquidus Temperature1,390°C2,534 °F

Mechanical16

254 SMO-CD has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 195 GPa (28.3 Msi).

Elastic (Young's) Modulus195 GPa28.3 Msi
Shear Modulus75 GPa10.9 Msi
Bulk Modulus162 GPa23.5 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)850 MPa123 ksi
Yield Strength (0.2% offset)620 MPa89.9 ksi
Elongation at Break25%
Reduction in Area65%
Compressive Strength350 MPa50.8 ksi
Shear Strength430 MPa62.4 ksi
Fatigue Strength (Endurance Limit)300 MPa43.5 ksi
Fracture Toughness (K_IC)220 MPa·√m200 ksi·√in
Charpy V-Notch Impact (RT)120 J88.5 ft·lbf
Hardness, Brinell260 HB
Hardness, Rockwell B90 HRB
Hardness, Vickers200 HV

Thermal6

254 SMO-CD is rated for continuous service to 400°C (752 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).

Thermal Conductivity14 W/m·K8.1 BTU/hr·ft·°F
Specific Heat Capacity500 J/kg·K0.12 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)16.5 µm/m·K9.2 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-196°C-321 °F

Electrical3

254 SMO-CD conducts electricity at 2 % IACS, worse than 78% of stainless steel grades.

Electrical Conductivity2 % IACS
Electrical Resistivity8.5×10⁻⁷ Ω·m33.5 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is very good (84/100), better than 91% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceVery good84/100
Chemical Resistance SummaryExcellent in chloride-bearing and oxidising-acid media: resists pitting/crevice attack in seawater to ~40 °C, sulphuric acid up to ~40 % at moderate temperature, phosphoric and organic acids, and bleach/chlorine dioxide; not suitable for hot concentrated hydrochloric acid or strong reducing HF media.

Sustainability4

Producing a kilogram of 254 SMO-CD takes about 85 MJ of energy and emits 6.5 kg of CO₂ — more than 91% of stainless steel grades. Typical recycled content is 45%.

Embodied Energy (primary production)85 MJ/kg36,543 BTU/lb
Embodied Carbon (primary production)6.5 kg CO₂/kg
Embodied Water120 L/kg14.4 gal/lb
Typical Recycled Content45%

Manufacturability8

254 SMO-CD's machinability is poor (25/100, worse than 88% of stainless steel grades); weldability very good (75/100); formability fair (40/100).

MachinabilityPoor25/100
Machinability Rating (AISI 1212 = 100 %)33%
WeldabilityVery good75/100
Formability (cold)Fair40/100
CastabilityFair35/100
Brazeability / SolderabilityGood55/100
PolishabilityVery good80/100
Anodizing Responsen/a — ferrous alloy; use pickling/passivation or electropolishing instead

Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.

Other 254 SMO tempers and conditions

254 SMO is also supplied in 4 other conditions. The full side-by-side table is on the 254 SMO overview.

Working with 254 SMO-CD

Is 254 SMO easy to machine?

Machine like a nickel alloy: rigid setup, sharp positive-rake carbide, low speed with heavy positive feed, flood coolant, and never dwell — the surface work-hardens instantly.

Can 254 SMO be welded?

Weld with over-alloyed Ni-base filler (ERNiCrMo-3/625 or ERNiCrMo-4/C-276), low heat input, interpass < 100 °C, argon backing; no preheat or PWHT, and pickle/passivate the heat tint.

Can 254 SMO be formed, bent or molded?

Cold forms well but needs ~50 % more press force than 316L and generous springback allowance; hot work 1150–1200 °C followed by mandatory solution anneal and quench.

What surface finishes work on 254 SMO?

Pickle in HNO₃–HF or electropolish to restore the passive film; mechanical polish to Ra < 0.5 µm gives best crevice performance — do not use carbon-steel-contaminated abrasives.

254 SMO 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.

ElementSpec limit (wt %)Nominal
Clow carbon for intergranular resistance≤ 0.020.01
Si≤ 0.80.4
Mn≤ 10.6
P≤ 0.030.02
S≤ 0.010
Cr19.5 – 20.520
Ni17.5 – 18.518
Mo6 – 6.56.2
Cu0.5 – 10.7
N0.18 – 0.220.2
Febalance, ~54 %balance—

254 SMO-CD — frequently asked

What is 254 SMO-CD used for?

254 SMO-CD is typically used for seawater pipework and manifolds, offshore platform piping and tubing, flue-gas desulfurization scrubbers, heat exchanger plates and tubesheets, desalination evaporator components and chemical tanker cargo tanks. In short: pitting-resistant super-austenitic.

What is the yield strength of 254 SMO-CD?

254 SMO-CD has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.

Is 254 SMO-CD easy to machine?

Not especially — machinability is rated poor (25/100, worse than 88% of stainless steel grades). Machine like a nickel alloy: rigid setup, sharp positive-rake carbide, low speed with heavy positive feed, flood coolant, and never dwell — the surface work-hardens instantly.

Can 254 SMO-CD be welded?

Yes — weldability is rated very good (75/100). Weld with over-alloyed Ni-base filler (ERNiCrMo-3/625 or ERNiCrMo-4/C-276), low heat input, interpass < 100 °C, argon backing; no preheat or PWHT, and pickle/passivate the heat tint.

What surface finishes work on 254 SMO-CD?

Pickle in HNO₃–HF or electropolish to restore the passive film; mechanical polish to Ra < 0.5 µm gives best crevice performance — do not use carbon-steel-contaminated abrasives.

Can 254 SMO-CD be formed, bent or molded?

Cold forms well but needs ~50 % more press force than 316L and generous springback allowance; hot work 1150–1200 °C followed by mandatory solution anneal and quench.

What is the maximum service temperature of 254 SMO-CD?

254 SMO-CD is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 254 SMO Solution Annealed and 254 SMO-CD?

Solution Annealed is the default condition — standard supply condition for all product forms; maximum corrosion resistance and toughness. CD: pick for higher-strength fasteners, shafts and pump parts where tight tolerance and bright finish are needed. Yield strength is 350 MPa in Solution Annealed versus 620 MPa in CD.

Can FabDigit make parts in 254 SMO-CD?

Yes — 254 SMO-CD is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip (S31254) — ASTM International (2023)
  2. ASTM A182/A182M — Forged Fittings and Flanges (Grade F44) — ASTM International (2022)
  3. EN 10088-2 — Stainless steels, sheet/plate (1.4547) — CEN (2014)
  4. 254 SMO / Outokumpu Ultra 254 SMO alloy datasheet — Outokumpu (2022)
  5. Sandvik SANICRO 28 / 254 SMO-class 6Mo austenitic tube data — Alleima (Sandvik Materials Technology) (2021)
  6. 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.