Steel M41-ANN vs M41 HT66-68
Steel · M41 temper comparison
M41-ANN and M41 HT66-68 are two conditions of the same steel grade, M41: ANN (annealed) versus HT66-68 (hardened & triple tempered). The chemistry is identical, so every difference below comes from the condition. M41 HT66-68 is the stronger of the two: tensile strength 2,200 MPa (319 ksi) against 900 MPa (131 ksi) for M41-ANN, about 144% more. M41 HT66-68 is harder — 920 HV against 275 HV for M41-ANN — which matters for wear surfaces and threads. On the shop floor, M41-ANN machines more easily (poor vs not recommended).
M41-ANNChoose it when the part is machined in volume.
M41 HT66-68Choose it when strength drives the design, or when surface hardness matters.
M41-ANN vs M41 HT66-68: 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Compressive Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Shear Modulus 85 GPa12.3 Msi · Bulk Modulus 167 GPa24.2 Msi · Poisson's Ratio 0.28 · Yield Strength (0.2% offset) 600 MPa87 ksi · Elongation at Break 12% · Reduction in Area 20% · Shear Strength 560 MPa81.2 ksi · Hardness, Brinell 262 HB · Hardness, Rockwell B 100 HRB
Physical
Density and transition temperatures.
Same in both: Density 8.16 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,250°C2,282 °F · Liquidus Temperature 1,430°C2,606 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 21 W/m·K12.1 BTU/hr·ft·°F · Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.8 µm/m·K6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.52 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 18 / 100 · Formability (cold) 12 / 100 · Brazeability / Solderability 55 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.8 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 40%
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.
M41-ANN vs M41 HT66-68 — frequently asked
Is M41 HT66-68 stronger than M41-ANN?
Yes. M41 HT66-68 has a typical tensile strength of 2,200 MPa (319 ksi) against 900 MPa (131 ksi) for M41-ANN — about 144% more.
Which condition does FabDigit quote by default, ANN or HT66-68?
ANN is the default M41 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.
Which is easier to machine, M41-ANN or M41 HT66-68?
M41-ANN. Its machinability rates poor (30/100) against not recommended (4/100) for M41 HT66-68.
Ready to make it?
Upload a CAD file and FabDigit prices the part in M41-ANN and M41 HT66-68 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.