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Steel 20MoCr4 +H vs 20MoCr4 +U

Steel · 20MoCr4 temper comparison

20MoCr4 +H and 20MoCr4 +U are two conditions of the same steel grade, 20MoCr4: +H (supplied to the restricted hardenability (Jominy) band) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. 20MoCr4 +U is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 355 MPa (51.5 ksi) for 20MoCr4 +H, about 27% more; tensile strength follows at 700 MPa (102 ksi) vs 580 MPa (84.1 ksi). In exchange, 20MoCr4 +H is the more ductile: elongation 21% versus 16% for 20MoCr4 +U, and 20MoCr4 +U is harder (215 HB vs 185 HB). On the shop floor, 20MoCr4 +H machines more easily (good vs fair).

20MoCr4 +HChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

20MoCr4 +UChoose it when strength drives the design.

20MoCr4 +H vs 20MoCr4 +U: properties

20MoCr4 +H20MoCr4 +U

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

580 MPa84.1 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

355 MPa51.5 ksi
450 MPa65.3 ksi

Elongation at Break

21%
16%

Reduction in Area

55%
45%

Compressive Strength

360 MPa52.2 ksi
455 MPa66 ksi

Shear Strength

350 MPa50.8 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
330 MPa47.9 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

185 HB
215 HB

Hardness, Rockwell B

90 HRB
96 HRB

Hardness, Vickers

195 HV
226 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) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % 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 11 / 100

Manufacturability

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

Machinability

62 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

61%
50%

Weldability

55 / 100
50 / 100

Formability (cold)

55 / 100
42 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 60 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 33 MJ/kg14,187 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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 scale20MoCr4

20MoCr4 +H vs 20MoCr4 +U — frequently asked

Is 20MoCr4 +U stronger than 20MoCr4 +H?

Yes. 20MoCr4 +U has a typical yield strength of 450 MPa (65.3 ksi) against 355 MPa (51.5 ksi) for 20MoCr4 +H — about 27% more. Tensile strength is 700 MPa (102 ksi) vs 580 MPa (84.1 ksi).

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

+AC is the default 20MoCr4 condition in the FabDigit quote flow (neither +H nor +U). 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, 20MoCr4 +H or 20MoCr4 +U?

20MoCr4 +H. Its machinability rates good (62/100) against fair (52/100) for 20MoCr4 +U; for welding the order is 20MoCr4 +H first (good, 55/100) then 20MoCr4 +U (fair, 50/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20MoCr4 +H and 20MoCr4 +U 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.