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Steel M41-ANN vs M41 HT64-66

Steel · M41 temper comparison

M41-ANN and M41 HT64-66 are two conditions of the same steel grade, M41: ANN (annealed) versus HT64-66 (hardened & triple tempered). The chemistry is identical, so every difference below comes from the condition. M41 HT64-66 is the stronger of the two: tensile strength 2,300 MPa (334 ksi) against 900 MPa (131 ksi) for M41-ANN, about 156% more. In exchange, M41-ANN is the more ductile: elongation 12% versus 0.5% for M41 HT64-66, and M41 HT64-66 is harder (855 HV vs 275 HV). On the shop floor, M41-ANN machines more easily (poor vs not recommended).

M41-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

M41 HT64-66Choose it when strength drives the design.

M41-ANN vs M41 HT64-66: properties

M41-ANNM41 HT64-66

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

220 GPa31.9 Msi
217 GPa31.5 Msi

Tensile Strength (Ultimate)

900 MPa131 ksi
2,300 MPa334 ksi

Elongation at Break

12%
0.5%

Compressive Strength

950 MPa138 ksi
3,600 MPa522 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
780 MPa113 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
6 J4.4 ft·lbf

Hardness, Vickers

275 HV
855 HV

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 · 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.

Thermal Conductivity

21 W/m·K12.1 BTU/hr·ft·°F
20 W/m·K11.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

550°C1,022 °F
560°C1,040 °F

Same in both: 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.

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
7×10⁻⁷ Ω·m27.6 µΩ·in

Same in both: Electrical Conductivity 2.9 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
20 / 100

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

30 / 100
5 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
3%

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleM41

M41-ANN vs M41 HT64-66 — frequently asked

Is M41 HT64-66 stronger than M41-ANN?

Yes. M41 HT64-66 has a typical tensile strength of 2,300 MPa (334 ksi) against 900 MPa (131 ksi) for M41-ANN — about 156% more.

Which condition does FabDigit quote by default, ANN or HT64-66?

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 HT64-66?

M41-ANN. Its machinability rates poor (30/100) against not recommended (5/100) for M41 HT64-66.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M41-ANN and M41 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.