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Steel 46Cr2 +AC vs 46Cr2 +U

Steel · 46Cr2 temper comparison

46Cr2 +AC and 46Cr2 +U are two conditions of the same steel grade, 46Cr2: +AC (spheroidize annealed) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 46Cr2 +U is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 340 MPa (49.3 ksi) for 46Cr2 +AC, about 24% more; tensile strength follows at 720 MPa (104 ksi) vs 580 MPa (84.1 ksi). In exchange, 46Cr2 +AC is the more ductile: elongation 24% versus 17% for 46Cr2 +U, and 46Cr2 +U is harder (215 HB vs 175 HB). 46Cr2 +U runs hotter in service (400°C vs 300°C continuous). On the shop floor, 46Cr2 +AC machines more easily (good vs fair).

46Cr2 +ACChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

46Cr2 +UChoose it when strength drives the design, or when the part sees heat.

46Cr2 +AC vs 46Cr2 +U: properties

46Cr2 +AC46Cr2 +U

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

580 MPa84.1 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
420 MPa60.9 ksi

Elongation at Break

24%
17%

Reduction in Area

55%
45%

Compressive Strength

650 MPa94.3 ksi
430 MPa62.4 ksi

Shear Strength

360 MPa52.2 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

175 HB
215 HB

Hardness, Rockwell C

27 HRC
17 HRC

Hardness, Vickers

184 HV
225 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 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) 1,425°C2,597 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-25°C-13 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
8.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

62 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
55%

Weldability

35 / 100
40 / 100

Formability (cold)

65 / 100
35 / 100

Polishability

55 / 100
60 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Typical Recycled Content

30%
35%

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Water 60 L/kg7.2 gal/lb

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 scale46Cr2

46Cr2 +AC vs 46Cr2 +U — frequently asked

Is 46Cr2 +U stronger than 46Cr2 +AC?

Yes. 46Cr2 +U has a typical yield strength of 420 MPa (60.9 ksi) against 340 MPa (49.3 ksi) for 46Cr2 +AC — about 24% more. Tensile strength is 720 MPa (104 ksi) vs 580 MPa (84.1 ksi).

Which condition does FabDigit quote by default, +AC or +U?

+QT is the default 46Cr2 condition in the FabDigit quote flow (neither +AC nor +U). 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, 46Cr2 +AC or 46Cr2 +U?

46Cr2 +AC. Its machinability rates good (62/100) against fair (52/100) for 46Cr2 +U; for welding the order is 46Cr2 +U first (fair, 40/100) then 46Cr2 +AC (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 46Cr2 +AC and 46Cr2 +U 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.