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Steel 20MnCrMo4-2 +A vs 20MnCrMo4-2 +S

Steel · 20MnCrMo4-2 temper comparison

20MnCrMo4-2 +A and 20MnCrMo4-2 +S are two conditions of the same steel grade, 20MnCrMo4-2: +A (annealed) versus +S (treated for high shearability). The chemistry is identical, so every difference below comes from the condition. 20MnCrMo4-2 +A is the stronger of the two: yield strength 400 MPa (58 ksi) against 370 MPa (53.7 ksi) for 20MnCrMo4-2 +S, about 8% more; tensile strength follows at 620 MPa (89.9 ksi) vs 580 MPa (84.1 ksi). 20MnCrMo4-2 +A is harder — 195 HB against 175 HB for 20MnCrMo4-2 +S — which matters for wear surfaces and threads. On the shop floor, 20MnCrMo4-2 +S forms better (good vs fair).

20MnCrMo4-2 +AChoose it when strength drives the design, or when surface hardness matters.

20MnCrMo4-2 +A vs 20MnCrMo4-2 +S: properties

20MnCrMo4-2 +A20MnCrMo4-2 +S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
580 MPa84.1 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
370 MPa53.7 ksi

Elongation at Break

20%
22%

Reduction in Area

52%
55%

Compressive Strength

400 MPa58 ksi
370 MPa53.7 ksi

Shear Strength

380 MPa55.1 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

195 HB
175 HB

Hardness, Rockwell B

92 HRB
88 HRB

Hardness, Vickers

205 HV
184 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) 1,420°C2,588 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
43 W/m·K24.8 BTU/hr·ft·°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 270 J/g116 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 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) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

55 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

40 / 100
42 / 100

Formability (cold)

50 / 100
62 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 60 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 45 L/kg5.4 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 scale20MnCrMo4-2

20MnCrMo4-2 +A vs 20MnCrMo4-2 +S — frequently asked

Is 20MnCrMo4-2 +A stronger than 20MnCrMo4-2 +S?

Yes. 20MnCrMo4-2 +A has a typical yield strength of 400 MPa (58 ksi) against 370 MPa (53.7 ksi) for 20MnCrMo4-2 +S — about 8% more. Tensile strength is 620 MPa (89.9 ksi) vs 580 MPa (84.1 ksi).

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

+A is the default 20MnCrMo4-2 condition in the FabDigit quote flow. 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 20MnCrMo4-2 +A over 20MnCrMo4-2 +S?

Pick 20MnCrMo4-2 +A when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20MnCrMo4-2 +A and 20MnCrMo4-2 +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.