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Steel SK95-HR vs SK95-QT500

Steel · SK95 temper comparison

SK95-HR and SK95-QT500 are two conditions of the same steel grade, SK95: HR (hot rolled) versus QT500 (quenched + tempered 500 °C). The chemistry is identical, so every difference below comes from the condition. SK95-QT500 is the stronger of the two: yield strength 1,100 MPa (160 ksi) against 460 MPa (66.7 ksi) for SK95-HR, about 139% more; tensile strength follows at 1,280 MPa (186 ksi) vs 800 MPa (116 ksi). In exchange, SK95-HR is the more ductile: elongation 12% versus 9% for SK95-QT500, and SK95-QT500 is harder (380 HB vs 240 HB). On the shop floor, SK95-HR machines more easily (fair vs poor).

SK95-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SK95-QT500Choose it when strength drives the design.

SK95-HR vs SK95-QT500: properties

SK95-HRSK95-QT500

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
1,280 MPa186 ksi

Yield Strength (0.2% offset)

460 MPa66.7 ksi
1,100 MPa160 ksi

Elongation at Break

12%
9%

Reduction in Area

28%
22%

Compressive Strength

480 MPa69.6 ksi
1,450 MPa210 ksi

Shear Strength

500 MPa72.5 ksi
780 MPa113 ksi

Fatigue Strength (Endurance Limit)

355 MPa51.5 ksi
520 MPa75.4 ksi

Charpy V-Notch Impact (RT)

12 J8.9 ft·lbf
28 J20.7 ft·lbf

Hardness, Brinell

240 HB
380 HB

Hardness, Rockwell B

99 HRB
91 HRB

Hardness, Vickers

250 HV
400 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 7.83 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.

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Same in both: 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
9 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

42 / 100
28 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
23%

Weldability

15 / 100
8 / 100

Formability (cold)

30 / 100
15 / 100

Same in both: Castability 25 / 100 · Brazeability / Solderability 50 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 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 scaleSK95

SK95-HR vs SK95-QT500 — frequently asked

Is SK95-QT500 stronger than SK95-HR?

Yes. SK95-QT500 has a typical yield strength of 1,100 MPa (160 ksi) against 460 MPa (66.7 ksi) for SK95-HR — about 139% more. Tensile strength is 1,280 MPa (186 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, HR or QT500?

A is the default SK95 condition in the FabDigit quote flow (neither HR nor QT500). 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, SK95-HR or SK95-QT500?

SK95-HR. Its machinability rates fair (42/100) against poor (28/100) for SK95-QT500; for welding the order is SK95-HR first (poor, 15/100) then SK95-QT500 (not recommended, 8/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SK95-HR and SK95-QT500 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.