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Stainless Steel CN7M-F vs CN7M-ST

Stainless Steel · CN7M temper comparison

CN7M-F and CN7M-ST are two conditions of the same stainless steel grade, CN7M: F (as fabricated) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. CN7M-F is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 220 MPa (31.9 ksi) for CN7M-ST, about 9% more. In exchange, CN7M-ST is the more ductile: elongation 45% versus 25% for CN7M-F, and CN7M-F is harder (155 HB vs 140 HB). CN7M-ST runs hotter in service (500°C vs 425°C continuous). On the shop floor, CN7M-ST welds better (very good vs fair).

CN7M-FChoose it when strength drives the design.

CN7M-STChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

CN7M-F vs CN7M-ST: properties

CN7M-FCN7M-ST

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

460 MPa66.7 ksi
480 MPa69.6 ksi

Yield Strength (0.2% offset)

240 MPa34.8 ksi
220 MPa31.9 ksi

Elongation at Break

25%
45%

Reduction in Area

30%
55%

Compressive Strength

240 MPa34.8 ksi
220 MPa31.9 ksi

Shear Strength

320 MPa46.4 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
190 MPa27.6 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
160 MPa·√m146 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

155 HB
140 HB

Hardness, Rockwell B

84 HRB
78 HRB

Hardness, Vickers

163 HV
147 HV

Same in both: Elastic (Young's) Modulus 180 GPa26.1 Msi · Shear Modulus 69 GPa10 Msi · Bulk Modulus 150 GPa21.8 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Same in both: Density 8 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,425°C2,597 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

425°C797 °F
500°C932 °F

Same in both: Thermal Conductivity 12.6 W/m·K7.3 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14.7 µm/m·K8.2 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 1.6 % IACS · Electrical Resistivity 1.08×10⁻⁶ Ω·m42.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

60 / 100
85 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

32 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
38%

Weldability

50 / 100
70 / 100

Formability (cold)

30 / 100
40 / 100

Same in both: Castability 65 / 100 · Brazeability / Solderability 50 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 70 MJ/kg30,095 BTU/lb · Embodied Carbon (primary production) 5.5 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 60%

Strength versus weight

Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleCN7M

CN7M-F vs CN7M-ST — frequently asked

Is CN7M-F stronger than CN7M-ST?

Yes. CN7M-F has a typical yield strength of 240 MPa (34.8 ksi) against 220 MPa (31.9 ksi) for CN7M-ST — about 9% more. Tensile strength is 460 MPa (66.7 ksi) vs 480 MPa (69.6 ksi).

Which condition does FabDigit quote by default, F or ST?

ST is the default CN7M condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which welds better, CN7M-F or CN7M-ST?

CN7M-ST. Its weldability rates very good (70/100) against fair (50/100) for CN7M-F.

Ready to make it?

Upload a CAD file and FabDigit prices the part in CN7M-F and CN7M-ST side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.