Steel 18Kh2N4MA-A vs 18Kh2N4MA-HR
Steel · 18Kh2N4MA temper comparison
18Kh2N4MA-A and 18Kh2N4MA-HR are two conditions of the same steel grade, 18Kh2N4MA: A (solution annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 18Kh2N4MA-HR is the stronger of the two: yield strength 850 MPa (123 ksi) against 700 MPa (102 ksi) for 18Kh2N4MA-A, about 21% more; tensile strength follows at 1,150 MPa (167 ksi) vs 900 MPa (131 ksi). In exchange, 18Kh2N4MA-A is the more ductile: elongation 17% versus 12% for 18Kh2N4MA-HR, and 18Kh2N4MA-HR is harder (340 HB vs 255 HB). 18Kh2N4MA-A runs hotter in service (400°C vs 200°C continuous). On the shop floor, 18Kh2N4MA-A machines more easily (34 vs 18 out of 100).
18Kh2N4MA-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
18Kh2N4MA-HRChoose it when strength drives the design.
18Kh2N4MA-A vs 18Kh2N4MA-HR: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 163 GPa23.6 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
Max Service Temperature (continuous)
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 · Min Service Temperature -70°C-94 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Resistivity 3.5×10⁻⁷ Ω·m13.8 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 14 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.7 kg CO₂/kg · Embodied Water 70 L/kg8.4 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.
18Kh2N4MA-A vs 18Kh2N4MA-HR — frequently asked
Is 18Kh2N4MA-HR stronger than 18Kh2N4MA-A?
Yes. 18Kh2N4MA-HR has a typical yield strength of 850 MPa (123 ksi) against 700 MPa (102 ksi) for 18Kh2N4MA-A — about 21% more. Tensile strength is 1,150 MPa (167 ksi) vs 900 MPa (131 ksi).
Which condition does FabDigit quote by default, A or HR?
QT200 is the default 18Kh2N4MA 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, 18Kh2N4MA-A or 18Kh2N4MA-HR?
18Kh2N4MA-A, by a small margin. Both rate poor for machinability — 34/100 against 18/100 for 18Kh2N4MA-HR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 18Kh2N4MA-A and 18Kh2N4MA-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.