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Steel SKH57-ANN vs SKH57 QT-STEAM

Steel · SKH57 temper comparison

SKH57-ANN and SKH57 QT-STEAM are two conditions of the same steel grade, SKH57: ANN (annealed) versus QT-STEAM (hardened & tempered + steam oxide). The chemistry is identical, so every difference below comes from the condition. SKH57 QT-STEAM is the stronger of the two: yield strength 2,150 MPa (312 ksi) against 540 MPa (78.3 ksi) for SKH57-ANN, about 4.0 times as much; tensile strength follows at 2,600 MPa (377 ksi) vs 880 MPa (128 ksi). In exchange, SKH57-ANN is the more ductile: elongation 10% versus 1% for SKH57 QT-STEAM, and SKH57 QT-STEAM is harder (65 HRC vs 26 HRC). SKH57 QT-STEAM runs hotter in service (580°C vs 400°C continuous). On the shop floor, SKH57-ANN machines more easily (poor vs not recommended).

SKH57-ANNChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SKH57 QT-STEAMChoose it when strength drives the design, or when the part sees heat.

SKH57-ANN vs SKH57 QT-STEAM: properties

SKH57-ANNSKH57 QT-STEAM

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

225 GPa32.6 Msi
230 GPa33.4 Msi

Tensile Strength (Ultimate)

880 MPa128 ksi
2,600 MPa377 ksi

Yield Strength (0.2% offset)

540 MPa78.3 ksi
2,150 MPa312 ksi

Elongation at Break

10%
1%

Compressive Strength

1,000 MPa145 ksi
3,400 MPa493 ksi

Fracture Toughness (K_IC)

22 MPa·√m20 ksi·√in
14 MPa·√m12.7 ksi·√in

Hardness, Rockwell C

26 HRC
65 HRC

Hardness, Vickers

275 HV
850 HV

Same in both: Shear Modulus 86 GPa12.5 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 265 HB

Physical

Density and transition temperatures.

Same in both: Density 8.3 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,260°C2,300 °F · Liquidus Temperature 1,400°C2,552 °F

Thermal

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

Thermal Conductivity

19 W/m·K11 BTU/hr·ft·°F
21 W/m·K12.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
580°C1,076 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.2 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
2.7 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
6.5×10⁻⁷ Ω·m25.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

20 / 100
28 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V

Manufacturability

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

Machinability

25 / 100
5 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
5%

Weldability

12 / 100
8 / 100

Formability (cold)

8 / 100
2 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 60 MJ/kg25,795 BTU/lb · Embodied Carbon (primary production) 4.5 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 35%

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 scaleSKH57

SKH57-ANN vs SKH57 QT-STEAM — frequently asked

Is SKH57 QT-STEAM stronger than SKH57-ANN?

Yes. SKH57 QT-STEAM has a typical yield strength of 2,150 MPa (312 ksi) against 540 MPa (78.3 ksi) for SKH57-ANN — about 4.0 times as much. Tensile strength is 2,600 MPa (377 ksi) vs 880 MPa (128 ksi).

Which condition does FabDigit quote by default, ANN or QT-STEAM?

ANN is the default SKH57 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, SKH57-ANN or SKH57 QT-STEAM?

SKH57-ANN. Its machinability rates poor (25/100) against not recommended (5/100) for SKH57 QT-STEAM.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SKH57-ANN and SKH57 QT-STEAM 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.