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Stainless Steel CA15M-A vs CA15M-QT315

Stainless Steel · CA15M temper comparison

CA15M-A and CA15M-QT315 are two conditions of the same stainless steel grade, CA15M: A (solution annealed) versus QT315. The chemistry is identical, so every difference below comes from the condition. CA15M-QT315 is the stronger of the two: yield strength 830 MPa (120 ksi) against 415 MPa (60.2 ksi) for CA15M-A, about 100% more; tensile strength follows at 1,035 MPa (150 ksi) vs 640 MPa (92.8 ksi). In exchange, CA15M-A is the more ductile: elongation 28% versus 12% for CA15M-QT315, and CA15M-QT315 is harder (320 HB vs 180 HB). CA15M-A runs hotter in service (650°C vs 300°C continuous). On the shop floor, CA15M-A machines more easily (good vs poor).

CA15M-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

CA15M-QT315Choose it when strength drives the design.

CA15M-A vs CA15M-QT315: properties

CA15M-ACA15M-QT315

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

640 MPa92.8 ksi
1,035 MPa150 ksi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
830 MPa120 ksi

Elongation at Break

28%
12%

Reduction in Area

60%
35%

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
430 MPa62.4 ksi

Charpy V-Notch Impact (RT)

50 J36.9 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

180 HB
320 HB

Hardness, Rockwell C

20 HRC
34 HRC

Hardness, Vickers

190 HV
340 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 · Compressive Strength 560 MPa81.2 ksi · Shear Strength 450 MPa65.3 ksi · Fracture Toughness (K_IC) 80 MPa·√m72.8 ksi·√in

Physical

Density and transition temperatures.

Same in both: Density 7.61 g/cm³0.27 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Max Service Temperature (continuous)

650°C1,202 °F
300°C572 °F

Same in both: Thermal Conductivity 24.2 W/m·K14 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.8 µm/m·K6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3 % IACS · Electrical Resistivity 5.7×10⁻⁷ Ω·m22.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

42 / 100
40 / 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

55 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
30%

Same in both: Weldability 40 / 100 · Formability (cold) 10 / 100 · Castability 70 / 100 · Brazeability / Solderability 45 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4 kg CO₂/kg · Embodied Water 130 L/kg15.6 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 scaleCA15M

CA15M-A vs CA15M-QT315 — frequently asked

Is CA15M-QT315 stronger than CA15M-A?

Yes. CA15M-QT315 has a typical yield strength of 830 MPa (120 ksi) against 415 MPa (60.2 ksi) for CA15M-A — about 100% more. Tensile strength is 1,035 MPa (150 ksi) vs 640 MPa (92.8 ksi).

Which condition does FabDigit quote by default, A or QT315?

NT595 is the default CA15M condition in the FabDigit quote flow (neither A nor QT315). 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, CA15M-A or CA15M-QT315?

CA15M-A. Its machinability rates good (55/100) against poor (30/100) for CA15M-QT315.

Ready to make it?

Upload a CAD file and FabDigit prices the part in CA15M-A and CA15M-QT315 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.