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Steel 30CrMnSi-A vs 30CrMnSi QT880-250

Steel · 30CrMnSi temper comparison

30CrMnSi-A and 30CrMnSi QT880-250 are two conditions of the same steel grade, 30CrMnSi: A (solution annealed) versus QT880-250 (Q&T). The chemistry is identical, so every difference below comes from the condition. 30CrMnSi QT880-250 is the stronger of the two: yield strength 1,400 MPa (203 ksi) against 480 MPa (69.6 ksi) for 30CrMnSi-A, about 192% more; tensile strength follows at 1,650 MPa (239 ksi) vs 750 MPa (109 ksi). In exchange, 30CrMnSi-A is the more ductile: elongation 20% versus 6% for 30CrMnSi QT880-250, and 30CrMnSi QT880-250 is harder (460 HB vs 210 HB). 30CrMnSi-A runs hotter in service (400°C vs 180°C continuous). On the shop floor, 30CrMnSi-A machines more easily (good vs poor) and 30CrMnSi-A welds better (50 vs 40 out of 100).

30CrMnSi-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

30CrMnSi QT880-250Choose it when strength drives the design.

30CrMnSi-A vs 30CrMnSi QT880-250: properties

30CrMnSi-A30CrMnSi QT880-250

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

750 MPa109 ksi
1,650 MPa239 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
1,400 MPa203 ksi

Elongation at Break

20%
6%

Reduction in Area

55%
35%

Shear Strength

450 MPa65.3 ksi
990 MPa144 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
700 MPa102 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
42 MPa·√m38.2 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

210 HB
460 HB

Hardness, Rockwell C

36 HRC
48 HRC

Hardness, Vickers

355 HV
490 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 · Compressive Strength 930 MPa135 ksi

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)

400°C752 °F
180°C356 °F

Same in both: Thermal Conductivity 37 W/m·K21.4 BTU/hr·ft·°F · Specific Heat Capacity 470 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 270 J/g116 BTU/lb · Min Service Temperature -70°C-94 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 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

55 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
25%

Weldability

50 / 100
40 / 100

Formability (cold)

45 / 100
8 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 65 / 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 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 scale30CrMnSi

30CrMnSi-A vs 30CrMnSi QT880-250 — frequently asked

Is 30CrMnSi QT880-250 stronger than 30CrMnSi-A?

Yes. 30CrMnSi QT880-250 has a typical yield strength of 1,400 MPa (203 ksi) against 480 MPa (69.6 ksi) for 30CrMnSi-A — about 192% more. Tensile strength is 1,650 MPa (239 ksi) vs 750 MPa (109 ksi).

Which condition does FabDigit quote by default, A or QT880-250?

QT880-520 is the default 30CrMnSi condition in the FabDigit quote flow (neither A nor QT880-250). 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, 30CrMnSi-A or 30CrMnSi QT880-250?

30CrMnSi-A. Its machinability rates good (55/100) against poor (22/100) for 30CrMnSi QT880-250; for welding the order is 30CrMnSi-A first (fair, 50/100) then 30CrMnSi QT880-250 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 30CrMnSi-A and 30CrMnSi QT880-250 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.