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Steel M7-ANN vs M7 HT62-64

Steel · M7 temper comparison

M7-ANN and M7 HT62-64 are two conditions of the same steel grade, M7: ANN (annealed) versus HT62-64 (hardened & tempered, 62–64 HRC). The chemistry is identical, so every difference below comes from the condition. M7 HT62-64 is the stronger of the two: yield strength 1,950 MPa (283 ksi) against 520 MPa (75.4 ksi) for M7-ANN, about 3.8 times as much; tensile strength follows at 2,200 MPa (319 ksi) vs 830 MPa (120 ksi). In exchange, M7-ANN is the more ductile: elongation 18% versus 1% for M7 HT62-64, and M7 HT62-64 is harder (790 HV vs 248 HV). On the shop floor, M7-ANN machines more easily (poor vs not recommended).

M7-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

M7 HT62-64Choose it when strength drives the design.

M7-ANN vs M7 HT62-64: properties

M7-ANNM7 HT62-64

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
217 GPa31.5 Msi

Tensile Strength (Ultimate)

830 MPa120 ksi
2,200 MPa319 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
1,950 MPa283 ksi

Elongation at Break

18%
1%

Compressive Strength

1,600 MPa232 ksi
3,300 MPa479 ksi

Shear Strength

520 MPa75.4 ksi
1,400 MPa203 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
800 MPa116 ksi

Fracture Toughness (K_IC)

40 MPa·√m36.4 ksi·√in
18 MPa·√m16.4 ksi·√in

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
6 J4.4 ft·lbf

Hardness, Vickers

248 HV
790 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 30% · Hardness, Brinell 235 HB · Hardness, Rockwell B 99 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.95 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

24 W/m·K13.9 BTU/hr·ft·°F
23 W/m·K13.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

500°C932 °F
540°C1,004 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.9 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
20 / 100

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

32 / 100
8 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
5%

Weldability

12 / 100
8 / 100

Same in both: Formability (cold) 15 / 100 · Castability 25 / 100 · Brazeability / Solderability 45 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 44 MJ/kg18,917 BTU/lb · Embodied Carbon (primary production) 3.3 kg CO₂/kg · Embodied Water 70 L/kg8.4 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 scaleM7

M7-ANN vs M7 HT62-64 — frequently asked

Is M7 HT62-64 stronger than M7-ANN?

Yes. M7 HT62-64 has a typical yield strength of 1,950 MPa (283 ksi) against 520 MPa (75.4 ksi) for M7-ANN — about 3.8 times as much. Tensile strength is 2,200 MPa (319 ksi) vs 830 MPa (120 ksi).

Which condition does FabDigit quote by default, ANN or HT62-64?

ANN is the default M7 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, M7-ANN or M7 HT62-64?

M7-ANN. Its machinability rates poor (32/100) against not recommended (8/100) for M7 HT62-64.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M7-ANN and M7 HT62-64 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.