Steel M44-ANN vs M44 HT64-66
Steel · M44 temper comparison
M44-ANN and M44 HT64-66 are two conditions of the same steel grade, M44: ANN (annealed) versus HT64-66 (hardened & triple tempered). The chemistry is identical, so every difference below comes from the condition. M44 HT64-66 is the stronger of the two: tensile strength 2,200 MPa (319 ksi) against 930 MPa (135 ksi) for M44-ANN, about 137% more. In exchange, M44-ANN is the more ductile: elongation 12% versus 0.7% for M44 HT64-66, and M44 HT64-66 is harder (65 HRC vs 27 HRC). M44 HT64-66 runs hotter in service (620°C vs 500°C continuous). On the shop floor, M44-ANN machines more easily (poor vs not recommended).
M44-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
M44 HT64-66Choose it when strength drives the design, or when the part sees heat.
M44-ANN vs M44 HT64-66: 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)
Elongation at Break
Compressive Strength
Shear Strength
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 83 GPa12 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 620 MPa89.9 ksi · Reduction in Area 20% · Hardness, Brinell 269 HB
Physical
Density and transition temperatures.
Same in both: Density 8 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,240°C2,264 °F · Liquidus Temperature 1,420°C2,588 °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 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 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) -0.55 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 15 / 100 · Formability (cold) 12 / 100 · Castability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 48 MJ/kg20,636 BTU/lb · Embodied Carbon (primary production) 4 kg CO₂/kg · Embodied Water 90 L/kg10.8 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.
M44-ANN vs M44 HT64-66 — frequently asked
Is M44 HT64-66 stronger than M44-ANN?
Yes. M44 HT64-66 has a typical tensile strength of 2,200 MPa (319 ksi) against 930 MPa (135 ksi) for M44-ANN — about 137% more.
Which condition does FabDigit quote by default, ANN or HT64-66?
ANN is the default M44 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, M44-ANN or M44 HT64-66?
M44-ANN. Its machinability rates poor (28/100) against not recommended (4/100) for M44 HT64-66.
Ready to make it?
Upload a CAD file and FabDigit prices the part in M44-ANN and M44 HT64-66 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.