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Stainless Steel 1.3955-CF8A

Grade

EN 1.3955

CF8A = cF8A-type

Same chemistry but ferrite balanced to a higher level for greater strength where a stronger casting is specified.

Premium cost $$$

Values for the CF8A condition

Other 1.3955 tempers and conditions

1.3955 is listed in 5 conditions; see the grade overview at 1.3955.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Spheroidize annealed
Cheapest condition for non-corrosive structural or ornamental castings only; retained carbides make it sensitization-prone.25050030155 HB2.3 % IACS
STDefault
Solution annealed
Standard supply condition for all corrosion-service castings; dissolves carbides and restores maximum corrosion resistance and ductility.25552050140 HB—
Solution annealed after hot isostatic pressing
Choose for pressure-tight, radiographically clean castings (valve/pump bodies, nuclear and subsea parts) where micro-shrinkage must be closed.26554555145 HB2.3 % IACS
Centrifugally cast + solution annealed (ASTM A451 CPF8 type)
Pipe and cylinder forms with denser, finer structure and higher strength than static castings.27554545150 HB2.3 % IACS
CF8AThis page
CF8A-type
Same chemistry but ferrite balanced to a higher level for greater strength where a stronger casting is specified.28557045155 HB2.4 % IACS

What is 1.3955-CF8A?

1.3955-CF8A is 1.3955 in the CF8A grade — same chemistry but ferrite balanced to a higher level for greater strength where a stronger casting is specified. 1.3955-CF8A has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi). 1.3955-CF8A has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). ST is the default condition FabDigit quotes; CF8A is available on request or by drawing note.

Advantages

  • Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades

Limitations

  • Limited formability — 20/100, worse than 86% of stainless steel grades
  • Hard to polish — 60/100, worse than 80% of stainless steel grades

1.3955-CF8A properties

Typical room-temperature values for 1.3955-CF8A; 23 are specific to this condition. Other listed values are 1.3955 reference data and may not represent this condition. Bars are the position among stainless steel grades.

Physical3

1.3955-CF8A has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).

Density7.75 g/cm³0.28 lb/in³
Melting Point (Solidus)1,400°C2,552 °F
Liquidus Temperature1,450°C2,642 °F

Mechanical16

1.3955-CF8A has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi).

Elastic (Young's) Modulus193 GPa28 Msi
Shear Modulus75 GPa10.9 Msi
Bulk Modulus145 GPa21 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)570 MPa82.7 ksi
Yield Strength (0.2% offset)285 MPa41.3 ksi
Elongation at Break45%
Reduction in Area50%
Compressive Strength285 MPa41.3 ksi
Shear Strength415 MPa60.2 ksi
Fatigue Strength (Endurance Limit)245 MPa35.5 ksi
Fracture Toughness (K_IC)170 MPa·√m155 ksi·√in
Charpy V-Notch Impact (RT)95 J70.1 ft·lbf
Hardness, Brinell155 HB
Hardness, Rockwell B82 HRB
Hardness, Vickers163 HV

Thermal6

1.3955-CF8A is rated for continuous service to 425°C (797 °F). It conducts heat at 16.5 W/m·K (9.53 BTU/hr·ft·°F), better than 70% of stainless steel grades. Thermal expansion is 17.3 µm/m·K (9.61 µin/in·°F).

Thermal Conductivity16.5 W/m·K9.5 BTU/hr·ft·°F
Specific Heat Capacity500 J/kg·K0.12 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)17.3 µm/m·K9.6 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)425°C797 °F
Min Service Temperature-196°C-321 °F

Electrical3

1.3955-CF8A conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.

Electrical Conductivity2.4 % IACS
Electrical Resistivity7.2×10⁻⁷ Ω·m28.3 µΩ·in
Magnetic Responseweakly magnetic

Chemical & Environmental3

Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.08 V
Corrosion ResistanceGood60/100
Chemical Resistance SummaryGood in oxidizing acids (nitric), water, steam, most organics and mild alkalis; poor against hydrochloric/hydrofluoric acids, hot chloride solutions (pitting/SCC) and reducing sulfuric acid; sensitization above ~425 °C causes intergranular attack.

Sustainability4

Producing a kilogram of 1.3955-CF8A takes about 58 MJ of energy and emits 4.2 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 70%.

Embodied Energy (primary production)58 MJ/kg24,936 BTU/lb
Embodied Carbon (primary production)4.2 kg CO₂/kg
Embodied Water130 L/kg15.6 gal/lb
Typical Recycled Content70%

Manufacturability8

1.3955-CF8A's machinability is fair (36/100, better than 57% of stainless steel grades); weldability very good (75/100); formability poor (20/100).

MachinabilityFair36/100
Machinability Rating (AISI 1212 = 100 %)36%
WeldabilityVery good75/100
Formability (cold)Poor20/100
CastabilityVery good80/100
Brazeability / SolderabilityGood55/100
PolishabilityGood60/100
Anodizing Responsen/a — stainless steel is not anodized; use pickling and passivation (ASTM A967) or electropolishing

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 1.3955-CF8A

Is 1.3955 easy to machine?

Gummy and work-hardening: use sharp positive-rake carbide, heavy positive feed to cut under the hardened skin, ~60–110 m/min, flood coolant; avoid dwelling.

Can 1.3955 be welded?

Readily welded with ER308/E308 (or 308L for as-welded corrosion service) by GTAW/SMAW; no preheat, keep interpass below ~150 °C and post-weld solution anneal for critical corrosion duty.

Can 1.3955 be formed, bent or molded?

Sand, investment and centrifugal casting all suitable; good fluidity with ~2.0–2.5 % solidification shrinkage — feed heavy sections generously and control ferrite (FN 5–15) to avoid hot tearing.

What surface finishes work on 1.3955?

Pickle and passivate (ASTM A967) or shot blast + electropolish; cannot be anodized, and casting skin porosity limits mirror polishing.

1.3955 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
CASTM A743 CF8 limit; EN GX12CrNi18-11 allows up to ~0.15 C≤ 0.080.06
Mn≤ 1.50.8
Sihigh Si aids fluidity≤ 21.2
P≤ 0.040.03
S≤ 0.040.02
Cr18 – 2119.5
Ni8 – 119.5
Moresidual only≤ 0.50.2
Febalance—

1.3955-CF8A — frequently asked

What is 1.3955-CF8A used for?

1.3955-CF8A is typically used for valve bodies, pump casings and process piping fittings. In short: general-purpose cast 304; service to 760 °C; widely available casting grade.

What is the yield strength of 1.3955-CF8A?

1.3955-CF8A has a typical yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.

Is 1.3955-CF8A easy to machine?

Not especially — machinability is rated fair (36/100, better than 57% of stainless steel grades). Gummy and work-hardening: use sharp positive-rake carbide, heavy positive feed to cut under the hardened skin, ~60–110 m/min, flood coolant; avoid dwelling.

Can 1.3955-CF8A be welded?

Yes — weldability is rated very good (75/100). Readily welded with ER308/E308 (or 308L for as-welded corrosion service) by GTAW/SMAW; no preheat, keep interpass below ~150 °C and post-weld solution anneal for critical corrosion duty.

What surface finishes work on 1.3955-CF8A?

Pickle and passivate (ASTM A967) or shot blast + electropolish; cannot be anodized, and casting skin porosity limits mirror polishing.

Can 1.3955-CF8A be formed, bent or molded?

Sand, investment and centrifugal casting all suitable; good fluidity with ~2.0–2.5 % solidification shrinkage — feed heavy sections generously and control ferrite (FN 5–15) to avoid hot tearing.

What is the maximum service temperature of 1.3955-CF8A?

1.3955-CF8A is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 1.3955-ST and 1.3955-CF8A?

ST is the default condition — standard supply condition for all corrosion-service castings; dissolves carbides and restores maximum corrosion resistance and ductility. CF8A: same chemistry but ferrite balanced to a higher level for greater strength where a stronger casting is specified. Yield strength is 255 MPa in ST versus 285 MPa in CF8A.

Sources

  1. ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application (grade CF8) — ASTM International (2019)
  2. ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CF8, CF8A) — ASTM International (2018)
  3. EN 10213 — Steel castings for pressure purposes — CEN (2016)
  4. ASM Specialty Handbook: Stainless Steels — ASM International (1994)
  5. Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
  6. ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)

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.