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Steel 34MnB5-A vs 34MnB5-HR

Steel · 34MnB5 temper comparison

34MnB5-A and 34MnB5-HR are two conditions of the same steel grade, 34MnB5: A (solution annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 34MnB5-HR is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 340 MPa (49.3 ksi) for 34MnB5-A, about 32% more; tensile strength follows at 680 MPa (98.6 ksi) vs 560 MPa (81.2 ksi). In exchange, 34MnB5-A is the more ductile: elongation 22% versus 16% for 34MnB5-HR, and 34MnB5-HR is harder (200 HB vs 165 HB). On the shop floor, 34MnB5-A welds better (good vs fair).

34MnB5-AChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

34MnB5-HRChoose it when strength drives the design.

34MnB5-A vs 34MnB5-HR: properties

34MnB5-A34MnB5-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
680 MPa98.6 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
450 MPa65.3 ksi

Elongation at Break

22%
16%

Reduction in Area

55%
45%

Shear Strength

340 MPa49.3 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
305 MPa44.2 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
58 MPa·√m52.8 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

165 HB
200 HB

Hardness, Rockwell B

85 HRB
93 HRB

Hardness, Vickers

172 HV
210 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.15×10⁻⁷ Ω·m8.46 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Same in both: Electrical Conductivity 8 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

60 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
56%

Weldability

60 / 100
50 / 100

Formability (cold)

70 / 100
55 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

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 scale34MnB5

34MnB5-A vs 34MnB5-HR — frequently asked

Is 34MnB5-HR stronger than 34MnB5-A?

Yes. 34MnB5-HR has a typical yield strength of 450 MPa (65.3 ksi) against 340 MPa (49.3 ksi) for 34MnB5-A — about 32% more. Tensile strength is 680 MPa (98.6 ksi) vs 560 MPa (81.2 ksi).

Which condition does FabDigit quote by default, A or HR?

CR is the default 34MnB5 condition in the FabDigit quote flow (neither A nor HR). 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, 34MnB5-A or 34MnB5-HR?

34MnB5-A. Its machinability rates good (60/100) against fair (52/100) for 34MnB5-HR; for welding the order is 34MnB5-A first (good, 60/100) then 34MnB5-HR (fair, 50/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5-A and 34MnB5-HR 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.