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Steel 12CrMo4 +A vs 12CrMo4 +AR

Steel · 12CrMo4 temper comparison

12CrMo4 +A and 12CrMo4 +AR are two conditions of the same steel grade, 12CrMo4: +A (annealed) versus +AR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 12CrMo4 +AR is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for 12CrMo4 +A, about 13% more; tensile strength follows at 520 MPa (75.4 ksi) vs 480 MPa (69.6 ksi). In exchange, 12CrMo4 +A is the more ductile: elongation 27% versus 22% for 12CrMo4 +AR, and 12CrMo4 +AR is harder (165 HB vs 150 HB).

12CrMo4 +AChoose it when the part is bent, formed or impact-loaded.

12CrMo4 +ARChoose it when strength drives the design.

12CrMo4 +A vs 12CrMo4 +AR: properties

12CrMo4 +A12CrMo4 +AR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

480 MPa69.6 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
340 MPa49.3 ksi

Elongation at Break

27%
22%

Reduction in Area

62%
55%

Compressive Strength

300 MPa43.5 ksi
340 MPa49.3 ksi

Shear Strength

300 MPa43.5 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

225 MPa32.6 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

150 HB
165 HB

Hardness, Rockwell B

80 HRB
85 HRB

Hardness, Vickers

155 HV
173 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 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)

500°C932 °F
480°C896 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 13 / 100

Manufacturability

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

Machinability

62 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

66%
60%

Weldability

72 / 100
68 / 100

Formability (cold)

68 / 100
52 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 25%

Strength versus weight

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

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale12CrMo4

12CrMo4 +A vs 12CrMo4 +AR — frequently asked

Is 12CrMo4 +AR stronger than 12CrMo4 +A?

Yes. 12CrMo4 +AR has a typical yield strength of 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for 12CrMo4 +A — about 13% more. Tensile strength is 520 MPa (75.4 ksi) vs 480 MPa (69.6 ksi).

Which condition does FabDigit quote by default, +A or +AR?

+N is the default 12CrMo4 condition in the FabDigit quote flow (neither +A nor +AR). 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, 12CrMo4 +A or 12CrMo4 +AR?

12CrMo4 +A, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 12CrMo4 +AR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 12CrMo4 +A and 12CrMo4 +AR 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.