Steel 20MnCr4-2 +AC vs 20MnCr4-2 +S
Steel · 20MnCr4-2 temper comparison
20MnCr4-2 +AC and 20MnCr4-2 +S are two conditions of the same steel grade, 20MnCr4-2: +AC (spheroidize annealed) versus +S (treated for high shearability). The chemistry is identical, so every difference below comes from the condition. 20MnCr4-2 +S is the stronger of the two: yield strength 400 MPa (58 ksi) against 320 MPa (46.4 ksi) for 20MnCr4-2 +AC, about 25% more; tensile strength follows at 630 MPa (91.4 ksi) vs 500 MPa (72.5 ksi). In exchange, 20MnCr4-2 +AC is the more ductile: elongation 26% versus 18% for 20MnCr4-2 +S, and 20MnCr4-2 +S is harder (190 HB vs 165 HB).
20MnCr4-2 +ACChoose it when the part is bent, formed or impact-loaded.
20MnCr4-2 +SChoose it when strength drives the design.
20MnCr4-2 +AC vs 20MnCr4-2 +S: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 360 MPa52.2 ksi · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in
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 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 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 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 8.5 % IACS · Electrical Resistivity 2×10⁻⁷ Ω·m7.87 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 55 / 100 · Castability 30 / 100 · Brazeability / Solderability 60 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%
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.
20MnCr4-2 +AC vs 20MnCr4-2 +S — frequently asked
Is 20MnCr4-2 +S stronger than 20MnCr4-2 +AC?
Yes. 20MnCr4-2 +S has a typical yield strength of 400 MPa (58 ksi) against 320 MPa (46.4 ksi) for 20MnCr4-2 +AC — about 25% more. Tensile strength is 630 MPa (91.4 ksi) vs 500 MPa (72.5 ksi).
Which condition does FabDigit quote by default, +AC or +S?
+A is the default 20MnCr4-2 condition in the FabDigit quote flow (neither +AC nor +S). 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.
When should I choose 20MnCr4-2 +AC over 20MnCr4-2 +S?
Pick 20MnCr4-2 +AC when the part is bent, formed or impact-loaded. Pick 20MnCr4-2 +S when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 20MnCr4-2 +AC and 20MnCr4-2 +S 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.