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Steel 4130-CR vs 4130 Q&T

Steel · 4130 temper comparison

4130-CR and 4130 Q&T are two conditions of the same steel grade, 4130: CR (cold rolled) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 4130 Q&T is the stronger of the two: yield strength 910 MPa (132 ksi) against 690 MPa (100 ksi) for 4130-CR, about 32% more; tensile strength follows at 1,030 MPa (149 ksi) vs 810 MPa (117 ksi). 4130 Q&T is the more ductile: elongation 18% versus 12% for 4130-CR, and 4130 Q&T is harder (302 HB vs 240 HB). 4130 Q&T runs hotter in service (400°C vs 300°C continuous). On the shop floor, 4130-CR machines more easily (good vs fair) and 4130-CR welds better (good vs fair).

4130-CRChoose it when the part is machined in volume, or when it will be welded.

4130 Q&TChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

4130-CR vs 4130 Q&T: properties

4130-CR4130 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

810 MPa117 ksi
1,030 MPa149 ksi

Yield Strength (0.2% offset)

690 MPa100 ksi
910 MPa132 ksi

Elongation at Break

12%
18%

Reduction in Area

45%
58%

Compressive Strength

700 MPa102 ksi
940 MPa136 ksi

Shear Strength

490 MPa71.1 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
480 MPa69.6 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
65 J47.9 ft·lbf

Hardness, Brinell

240 HB
302 HB

Hardness, Rockwell B

100 HRB
95 HRB

Hardness, Vickers

252 HV
318 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 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) 1,432°C2,610 °F · Liquidus Temperature 1,510°C2,750 °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 42.7 W/m·K24.7 BTU/hr·ft·°F · Specific Heat Capacity 477 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 272 J/g117 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.7 % IACS · Electrical Resistivity 2.23×10⁻⁷ Ω·m8.78 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 14 / 100

Manufacturability

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

Machinability

58 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
50%

Weldability

60 / 100
45 / 100

Formability (cold)

30 / 100
20 / 100

Same in both: Brazeability / Solderability 70 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 45 L/kg5.4 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 scale4130

4130-CR vs 4130 Q&T — frequently asked

Is 4130 Q&T stronger than 4130-CR?

Yes. 4130 Q&T has a typical yield strength of 910 MPa (132 ksi) against 690 MPa (100 ksi) for 4130-CR — about 32% more. Tensile strength is 1,030 MPa (149 ksi) vs 810 MPa (117 ksi).

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

HR is the default 4130 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, 4130-CR or 4130 Q&T?

4130-CR. Its machinability rates good (58/100) against fair (45/100) for 4130 Q&T; for welding the order is 4130-CR first (good, 60/100) then 4130 Q&T (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4130-CR and 4130 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.