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Steel 5140-CR vs 5140 Q&T

Steel · 5140 temper comparison

5140-CR and 5140 Q&T are two conditions of the same steel grade, 5140: CR (cold rolled) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 5140 Q&T is the stronger of the two: yield strength 860 MPa (125 ksi) against 620 MPa (89.9 ksi) for 5140-CR, about 39% more; tensile strength follows at 1,000 MPa (145 ksi) vs 760 MPa (110 ksi). 5140 Q&T is the more ductile: elongation 17.5% versus 10% for 5140-CR, and 5140 Q&T is harder (302 HB vs 217 HB). 5140 Q&T runs hotter in service (400°C vs 300°C continuous).

5140 Q&TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

5140-CR vs 5140 Q&T: properties

5140-CR5140 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
860 MPa125 ksi

Elongation at Break

10%
17.5%

Reduction in Area

40%
58%

Compressive Strength

630 MPa91.4 ksi
450 MPa65.3 ksi

Shear Strength

460 MPa66.7 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
470 MPa68.2 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
50 J36.9 ft·lbf

Hardness, Brinell

217 HB
302 HB

Hardness, Rockwell B

96 HRB
94 HRB

Hardness, Vickers

228 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 1,490°C2,714 °F

Thermal

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

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 473 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 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °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) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

56 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
55%

Formability (cold)

30 / 100
40 / 100

Same in both: Weldability 35 / 100 · Castability 30 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 1.9 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 scale5140

5140-CR vs 5140 Q&T — frequently asked

Is 5140 Q&T stronger than 5140-CR?

Yes. 5140 Q&T has a typical yield strength of 860 MPa (125 ksi) against 620 MPa (89.9 ksi) for 5140-CR — about 39% more. Tensile strength is 1,000 MPa (145 ksi) vs 760 MPa (110 ksi).

Which condition does FabDigit quote by default, CR or Q&T?

HR is the default 5140 condition in the FabDigit quote flow (neither CR nor Q&T). 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, 5140-CR or 5140 Q&T?

5140-CR. Its machinability rates good (56/100) against fair (50/100) for 5140 Q&T.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 5140-CR and 5140 Q&T 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.