Steel 905M39-ANN vs 905M39 QT+NIT
Steel · 905M39 temper comparison
905M39-ANN and 905M39 QT+NIT are two conditions of the same steel grade, 905M39: ANN (annealed) versus QT+NIT (Q&T (cond. V/W) + gas nitrided case). The chemistry is identical, so every difference below comes from the condition. 905M39 QT+NIT is the stronger of the two: yield strength 840 MPa (122 ksi) against 450 MPa (65.3 ksi) for 905M39-ANN, about 87% more; tensile strength follows at 1,075 MPa (156 ksi) vs 700 MPa (102 ksi). In exchange, 905M39-ANN is the more ductile: elongation 20% versus 12% for 905M39 QT+NIT, and 905M39 QT+NIT is harder (320 HB vs 210 HB). On the shop floor, 905M39-ANN machines more easily (good vs not recommended).
905M39-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
905M39 QT+NITChoose it when strength drives the design.
905M39-ANN vs 905M39 QT+NIT: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 720 MPa104 ksi · Shear Strength 560 MPa81.2 ksi · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 7.76 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,480°C2,696 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 33 W/m·K19.1 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 500°C932 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
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 15 / 100 · Brazeability / Solderability 35 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 BTU/lb · Embodied Carbon (primary production) 2.3 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.
905M39-ANN vs 905M39 QT+NIT — frequently asked
Is 905M39 QT+NIT stronger than 905M39-ANN?
Yes. 905M39 QT+NIT has a typical yield strength of 840 MPa (122 ksi) against 450 MPa (65.3 ksi) for 905M39-ANN — about 87% more. Tensile strength is 1,075 MPa (156 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, ANN or QT+NIT?
T is the default 905M39 condition in the FabDigit quote flow (neither ANN nor QT+NIT). 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, 905M39-ANN or 905M39 QT+NIT?
905M39-ANN. Its machinability rates good (55/100) against not recommended (8/100) for 905M39 QT+NIT.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 905M39-ANN and 905M39 QT+NIT 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.