FabDigitFabDigit

Stainless Steel CA15-AC vs CA15-H

Stainless Steel · CA15 temper comparison

CA15-AC and CA15-H are two conditions of the same stainless steel grade, CA15: AC (spheroidize annealed) versus H (hardened). The chemistry is identical, so every difference below comes from the condition. CA15-H is the stronger of the two: yield strength 1,100 MPa (160 ksi) against 620 MPa (89.9 ksi) for CA15-AC, about 77% more; tensile strength follows at 1,450 MPa (210 ksi) vs 800 MPa (116 ksi). In exchange, CA15-AC is the more ductile: elongation 8% versus 4% for CA15-H, and CA15-H is harder (430 HB vs 300 HB). CA15-AC runs hotter in service (400°C vs 300°C continuous). On the shop floor, CA15-AC machines more easily (poor vs not recommended) and CA15-AC welds better (25 vs 15 out of 100).

CA15-ACChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

CA15-HChoose it when strength drives the design.

CA15-AC vs CA15-H: properties

CA15-ACCA15-H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
1,450 MPa210 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
1,100 MPa160 ksi

Elongation at Break

8%
4%

Reduction in Area

20%
12%

Shear Strength

490 MPa71.1 ksi
870 MPa126 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
600 MPa87 ksi

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
28 MPa·√m25.5 ksi·√in

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

300 HB
430 HB

Hardness, Rockwell C

31 HRC
46 HRC

Hardness, Vickers

315 HV
460 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28

Physical

Density and transition temperatures.

Same in both: Density 7.61 g/cm³0.27 lb/in³ · Melting Point (Solidus) 1,480°C2,696 °F · Liquidus Temperature 1,530°C2,786 °F

Thermal

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

Max Service Temperature (continuous)

400°C752 °F
300°C572 °F

Same in both: Thermal Conductivity 24 W/m·K13.9 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.3 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -29°C-20 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
2.8 % IACS

Electrical Resistivity

5.9×10⁻⁷ Ω·m23.2 µΩ·in
6.1×10⁻⁷ Ω·m24 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

35 / 100
48 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V

Manufacturability

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

Machinability

28 / 100
12 / 100

Machinability Rating (AISI 1212 = 100 %)

28%
12%

Weldability

25 / 100
15 / 100

Formability (cold)

5 / 100
2 / 100

Same in both: Castability 70 / 100 · Brazeability / Solderability 40 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 40 MJ/kg17,197 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 180 L/kg21.6 gal/lb · Typical Recycled Content 75%

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 scaleCA15

CA15-AC vs CA15-H — frequently asked

Is CA15-H stronger than CA15-AC?

Yes. CA15-H has a typical yield strength of 1,100 MPa (160 ksi) against 620 MPa (89.9 ksi) for CA15-AC — about 77% more. Tensile strength is 1,450 MPa (210 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, AC or H?

NT650 is the default CA15 condition in the FabDigit quote flow (neither AC nor H). 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 is easier to machine, CA15-AC or CA15-H?

CA15-AC. Its machinability rates poor (28/100) against not recommended (12/100) for CA15-H; for welding the order is CA15-AC first (poor, 25/100) then CA15-H (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in CA15-AC and CA15-H 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.