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Steel 30CrNiMo8 Q&T vs 30CrNiMo8 Q&T 28-32 HRC

Steel · 30CrNiMo8 temper comparison

30CrNiMo8 Q&T and 30CrNiMo8 Q&T 28-32 HRC are two conditions of the same steel grade, 30CrNiMo8: Q&T (quenched and tempered) versus Q&T 28-32 HRC (Q&T to 28–32 HRC). The chemistry is identical, so every difference below comes from the condition. 30CrNiMo8 Q&T is the stronger of the two: yield strength 1,000 MPa (145 ksi) against 830 MPa (120 ksi) for 30CrNiMo8 Q&T 28-32 HRC, about 20% more; tensile strength follows at 1,200 MPa (174 ksi) vs 1,000 MPa (145 ksi). In exchange, 30CrNiMo8 Q&T 28-32 HRC is the more ductile: elongation 15% versus 12% for 30CrNiMo8 Q&T, and 30CrNiMo8 Q&T is harder (355 HB vs 285 HB). On the shop floor, 30CrNiMo8 Q&T 28-32 HRC machines more easily (48 vs 38 out of 100).

30CrNiMo8 Q&TChoose it when strength drives the design.

30CrNiMo8 Q&T 28-32 HRCChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

30CrNiMo8 Q&T vs 30CrNiMo8 Q&T 28-32 HRC: properties

30CrNiMo8 Q&T30CrNiMo8 Q&T 28-32 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,200 MPa174 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

1,000 MPa145 ksi
830 MPa120 ksi

Elongation at Break

12%
15%

Reduction in Area

50%
57%

Fatigue Strength (Endurance Limit)

550 MPa79.8 ksi
460 MPa66.7 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

355 HB
285 HB

Hardness, Rockwell C

38 HRC
30 HRC

Hardness, Vickers

375 HV
300 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 1,050 MPa152 ksi · Shear Strength 720 MPa104 ksi · Fracture Toughness (K_IC) 90 MPa·√m81.9 ksi·√in

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 1,480°C2,696 °F

Thermal

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

Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.5 % IACS · Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 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

38 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
50%

Same in both: Weldability 22 / 100 · Formability (cold) 18 / 100 · Brazeability / Solderability 45 / 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) 2.4 kg CO₂/kg · Embodied Water 55 L/kg6.6 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 scale30CrNiMo8

30CrNiMo8 Q&T vs 30CrNiMo8 Q&T 28-32 HRC — frequently asked

Is 30CrNiMo8 Q&T stronger than 30CrNiMo8 Q&T 28-32 HRC?

Yes. 30CrNiMo8 Q&T has a typical yield strength of 1,000 MPa (145 ksi) against 830 MPa (120 ksi) for 30CrNiMo8 Q&T 28-32 HRC — about 20% more. Tensile strength is 1,200 MPa (174 ksi) vs 1,000 MPa (145 ksi).

Which condition does FabDigit quote by default, Q&T or Q&T 28-32 HRC?

Q&T is the default 30CrNiMo8 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, 30CrNiMo8 Q&T or 30CrNiMo8 Q&T 28-32 HRC?

30CrNiMo8 Q&T 28-32 HRC, by a small margin. Both rate fair for machinability — 48/100 against 38/100 for 30CrNiMo8 Q&T.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 30CrNiMo8 Q&T and 30CrNiMo8 Q&T 28-32 HRC 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.