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Steel 42CrMoS4 +C vs 42CrMoS4 Q&T

Steel · 42CrMoS4 temper comparison

42CrMoS4 +C and 42CrMoS4 Q&T are two conditions of the same steel grade, 42CrMoS4: +C (cold drawn) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 42CrMoS4 Q&T is the stronger of the two: yield strength 720 MPa (104 ksi) against 660 MPa (95.7 ksi) for 42CrMoS4 +C, about 9% more; tensile strength follows at 1,000 MPa (145 ksi) vs 820 MPa (119 ksi). 42CrMoS4 Q&T is the more ductile: elongation 13% versus 9% for 42CrMoS4 +C, and 42CrMoS4 Q&T is harder (300 HB vs 245 HB). 42CrMoS4 Q&T runs hotter in service (425°C vs 350°C continuous). On the shop floor, 42CrMoS4 +C machines more easily (good vs fair).

42CrMoS4 +CChoose it when the part is machined in volume.

42CrMoS4 Q&TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

42CrMoS4 +C vs 42CrMoS4 Q&T: properties

42CrMoS4 +C42CrMoS4 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

820 MPa119 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

660 MPa95.7 ksi
720 MPa104 ksi

Elongation at Break

9%
13%

Reduction in Area

40%
45%

Compressive Strength

680 MPa98.6 ksi
830 MPa120 ksi

Shear Strength

490 MPa71.1 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

370 MPa53.7 ksi
480 MPa69.6 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

245 HB
300 HB

Hardness, Rockwell C

23 HRC
31 HRC

Hardness, Vickers

257 HV
315 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) 1,416°C2,581 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
425°C797 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.1 µm/m·K6.2 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8 % IACS

Electrical Resistivity

2.05×10⁻⁷ Ω·m8.07 µΩ·in
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) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

65 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

68%
52%

Formability (cold)

20 / 100
25 / 100

Same in both: Weldability 30 / 100 · Brazeability / Solderability 50 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.3 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 scale42CrMoS4

42CrMoS4 +C vs 42CrMoS4 Q&T — frequently asked

Is 42CrMoS4 Q&T stronger than 42CrMoS4 +C?

Yes. 42CrMoS4 Q&T has a typical yield strength of 720 MPa (104 ksi) against 660 MPa (95.7 ksi) for 42CrMoS4 +C — about 9% more. Tensile strength is 1,000 MPa (145 ksi) vs 820 MPa (119 ksi).

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

Q&T is the default 42CrMoS4 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, 42CrMoS4 +C or 42CrMoS4 Q&T?

42CrMoS4 +C. Its machinability rates good (65/100) against fair (50/100) for 42CrMoS4 Q&T.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 42CrMoS4 +C and 42CrMoS4 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.