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Steel 20KhN3A-A vs 20KhN3A-HR

Steel · 20KhN3A temper comparison

20KhN3A-A and 20KhN3A-HR are two conditions of the same steel grade, 20KhN3A: A (solution annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 20KhN3A-HR is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 430 MPa (62.4 ksi) for 20KhN3A-A, about 21% more; tensile strength follows at 820 MPa (119 ksi) vs 700 MPa (102 ksi). In exchange, 20KhN3A-A is the more ductile: elongation 21% versus 16% for 20KhN3A-HR, and 20KhN3A-HR is harder (240 HB vs 197 HB).

20KhN3A-AChoose it when the part is bent, formed or impact-loaded.

20KhN3A-HRChoose it when strength drives the design.

20KhN3A-A vs 20KhN3A-HR: properties

20KhN3A-A20KhN3A-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

700 MPa102 ksi
820 MPa119 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
520 MPa75.4 ksi

Elongation at Break

21%
16%

Reduction in Area

58%
50%

Compressive Strength

800 MPa116 ksi
530 MPa76.9 ksi

Shear Strength

590 MPa85.6 ksi
495 MPa71.8 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
370 MPa53.7 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

197 HB
240 HB

Hardness, Rockwell C

31 HRC
22 HRC

Hardness, Vickers

315 HV
252 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 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

34 W/m·K19.6 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Resistivity 2.8×10⁻⁷ Ω·m11 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 13 / 100

Manufacturability

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

Machinability

55 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
50%

Weldability

28 / 100
30 / 100

Formability (cold)

48 / 100
36 / 100

Same in both: Brazeability / Solderability 50 / 100 · Polishability 62 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 65 L/kg7.8 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale20KhN3A

20KhN3A-A vs 20KhN3A-HR — frequently asked

Is 20KhN3A-HR stronger than 20KhN3A-A?

Yes. 20KhN3A-HR has a typical yield strength of 520 MPa (75.4 ksi) against 430 MPa (62.4 ksi) for 20KhN3A-A — about 21% more. Tensile strength is 820 MPa (119 ksi) vs 700 MPa (102 ksi).

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

Q&T is the default 20KhN3A condition in the FabDigit quote flow (neither A nor HR). 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, 20KhN3A-A or 20KhN3A-HR?

20KhN3A-A. Its machinability rates good (55/100) against fair (48/100) for 20KhN3A-HR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20KhN3A-A and 20KhN3A-HR 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.