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Steel M34-A vs M34 HT-N

Steel · M34 temper comparison

M34-A and M34 HT-N are two conditions of the same steel grade, M34: A (solution annealed) versus HT-N (HT + surface treated). The chemistry is identical, so every difference below comes from the condition. M34 HT-N is the stronger of the two: yield strength 2,050 MPa (297 ksi) against 560 MPa (81.2 ksi) for M34-A, about 3.7 times as much; tensile strength follows at 2,300 MPa (334 ksi) vs 880 MPa (128 ksi). In exchange, M34-A is the more ductile: elongation 22% versus 0% for M34 HT-N, and M34 HT-N is harder (1,200 HV vs 250 HV). M34 HT-N runs hotter in service (620°C vs 550°C continuous). On the shop floor, M34-A machines more easily (fair vs not recommended) and M34-A welds better (poor vs not recommended).

M34-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

M34 HT-NChoose it when strength drives the design, or when the part sees heat.

M34-A vs M34 HT-N: properties

M34-AM34 HT-N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

217 GPa31.5 Msi
224 GPa32.5 Msi

Tensile Strength (Ultimate)

880 MPa128 ksi
2,300 MPa334 ksi

Yield Strength (0.2% offset)

560 MPa81.2 ksi
2,050 MPa297 ksi

Elongation at Break

22%
0%

Reduction in Area

35%
0%

Compressive Strength

1,600 MPa232 ksi
3,400 MPa493 ksi

Shear Strength

550 MPa79.8 ksi
1,550 MPa225 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
830 MPa120 ksi

Hardness, Vickers

250 HV
1,200 HV

Same in both: Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 235 HB · Hardness, Rockwell B 99 HRB

Physical

Density and transition temperatures.

Same in both: Density 8.03 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,240°C2,264 °F · Liquidus Temperature 1,425°C2,597 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

22 W/m·K12.7 BTU/hr·ft·°F
24 W/m·K13.9 BTU/hr·ft·°F

Max Service Temperature (continuous)

550°C1,022 °F
620°C1,148 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.7 µm/m·K5.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.2 % IACS
3 % IACS

Electrical Resistivity

5.4×10⁻⁷ Ω·m21.3 µΩ·in
5.7×10⁻⁷ Ω·m22.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
30 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.5 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

35 / 100
5 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
4%

Weldability

15 / 100
3 / 100

Formability (cold)

10 / 100
2 / 100

Same in both: Castability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 78 MJ/kg33,534 BTU/lb · Embodied Carbon (primary production) 5.6 kg CO₂/kg · Embodied Water 110 L/kg13.2 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 scaleM34

M34-A vs M34 HT-N — frequently asked

Is M34 HT-N stronger than M34-A?

Yes. M34 HT-N has a typical yield strength of 2,050 MPa (297 ksi) against 560 MPa (81.2 ksi) for M34-A — about 3.7 times as much. Tensile strength is 2,300 MPa (334 ksi) vs 880 MPa (128 ksi).

Which condition does FabDigit quote by default, A or HT-N?

A is the default M34 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, M34-A or M34 HT-N?

M34-A. Its machinability rates fair (35/100) against not recommended (5/100) for M34 HT-N; for welding the order is M34-A first (poor, 15/100) then M34 HT-N (not recommended, 3/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in M34-A and M34 HT-N 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.