Steel X11CrMo9-1 +A vs X11CrMo9-1 +I
Steel · X11CrMo9-1 temper comparison
X11CrMo9-1 +A and X11CrMo9-1 +I are two conditions of the same steel grade, X11CrMo9-1: +A (annealed) versus +I (isothermally annealed). The chemistry is identical, so every difference below comes from the condition. X11CrMo9-1 +I is the stronger of the two: yield strength 260 MPa (37.7 ksi) against 245 MPa (35.5 ksi) for X11CrMo9-1 +A, about 6% more. X11CrMo9-1 +I is harder — 160 HB against 150 HB for X11CrMo9-1 +A — which matters for wear surfaces and threads. On the shop floor, X11CrMo9-1 +A welds better (50 vs 40 out of 100).
X11CrMo9-1 +AChoose it when it will be welded.
X11CrMo9-1 +IChoose it when strength drives the design, or when surface hardness matters.
X11CrMo9-1 +A vs X11CrMo9-1 +I: 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 B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 213 GPa30.9 Msi · Shear Modulus 82 GPa11.9 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Same in both: Density 7.75 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 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.3 µm/m·K6.3 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V
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 40 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
X11CrMo9-1 +A vs X11CrMo9-1 +I — frequently asked
Is X11CrMo9-1 +I stronger than X11CrMo9-1 +A?
Yes. X11CrMo9-1 +I has a typical yield strength of 260 MPa (37.7 ksi) against 245 MPa (35.5 ksi) for X11CrMo9-1 +A — about 6% more. Tensile strength is 470 MPa (68.2 ksi) vs 455 MPa (66 ksi).
Which condition does FabDigit quote by default, +A or +I?
+NT is the default X11CrMo9-1 condition in the FabDigit quote flow (neither +A nor +I). 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 welds better, X11CrMo9-1 +A or X11CrMo9-1 +I?
X11CrMo9-1 +A. Its weldability rates fair (50/100) against fair (40/100) for X11CrMo9-1 +I.
Ready to make it?
Upload a CAD file and FabDigit prices the part in X11CrMo9-1 +A and X11CrMo9-1 +I 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.