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Steel 34CrMo4 +C vs 34CrMo4 +H

Steel · 34CrMo4 temper comparison

34CrMo4 +C and 34CrMo4 +H are two conditions of the same steel grade, 34CrMo4: +C (cold drawn) versus +H (hardened). The chemistry is identical, so every difference below comes from the condition. 34CrMo4 +H is the stronger of the two: yield strength 1,350 MPa (196 ksi) against 650 MPa (94.3 ksi) for 34CrMo4 +C, about 108% more; tensile strength follows at 1,750 MPa (254 ksi) vs 800 MPa (116 ksi). In exchange, 34CrMo4 +C is the more ductile: elongation 10% versus 4% for 34CrMo4 +H, and 34CrMo4 +H is harder (512 HB vs 240 HB). 34CrMo4 +C runs hotter in service (500°C vs 180°C continuous). On the shop floor, 34CrMo4 +C machines more easily (good vs poor) and 34CrMo4 +C welds better (fair vs poor).

34CrMo4 +CChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

34CrMo4 +HChoose it when strength drives the design.

34CrMo4 +C vs 34CrMo4 +H: properties

34CrMo4 +C34CrMo4 +H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
1,750 MPa254 ksi

Yield Strength (0.2% offset)

650 MPa94.3 ksi
1,350 MPa196 ksi

Elongation at Break

10%
4%

Reduction in Area

45%
15%

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
600 MPa87 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
40 MPa·√m36.4 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
10 J7.4 ft·lbf

Hardness, Brinell

240 HB
512 HB

Hardness, Rockwell C

22 HRC
52 HRC

Hardness, Vickers

252 HV
550 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 · Compressive Strength 780 MPa113 ksi · Shear Strength 620 MPa89.9 ksi

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 1,500°C2,732 °F

Thermal

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

Max Service Temperature (continuous)

500°C932 °F
180°C356 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

68 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
22%

Weldability

42 / 100
20 / 100

Formability (cold)

30 / 100
5 / 100

Same in both: Brazeability / Solderability 50 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 35%

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 scale34CrMo4

34CrMo4 +C vs 34CrMo4 +H — frequently asked

Is 34CrMo4 +H stronger than 34CrMo4 +C?

Yes. 34CrMo4 +H has a typical yield strength of 1,350 MPa (196 ksi) against 650 MPa (94.3 ksi) for 34CrMo4 +C — about 108% more. Tensile strength is 1,750 MPa (254 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, +C or +H?

+QT is the default 34CrMo4 condition in the FabDigit quote flow (neither +C nor +H). 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, 34CrMo4 +C or 34CrMo4 +H?

34CrMo4 +C. Its machinability rates good (68/100) against poor (22/100) for 34CrMo4 +H; for welding the order is 34CrMo4 +C first (fair, 42/100) then 34CrMo4 +H (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34CrMo4 +C and 34CrMo4 +H 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.