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Steel SKS93-HR vs SKS93 Q&T 58-61 HRC

Steel · SKS93 temper comparison

SKS93-HR and SKS93 Q&T 58-61 HRC are two conditions of the same steel grade, SKS93: HR (hot rolled) versus Q&T 58-61 HRC (oil quenched, tempered ~200 °C). The chemistry is identical, so every difference below comes from the condition. SKS93 Q&T 58-61 HRC is the stronger of the two: yield strength 1,850 MPa (268 ksi) against 520 MPa (75.4 ksi) for SKS93-HR, about 3.6 times as much; tensile strength follows at 2,100 MPa (305 ksi) vs 900 MPa (131 ksi). In exchange, SKS93-HR is the more ductile: elongation 10% versus 1% for SKS93 Q&T 58-61 HRC, and SKS93-HR is harder (260 HB vs 200 HB). On the shop floor, SKS93-HR machines more easily (poor vs not recommended).

SKS93-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SKS93 Q&T 58-61 HRCChoose it when strength drives the design.

SKS93-HR vs SKS93 Q&T 58-61 HRC: properties

SKS93-HRSKS93 Q&T 58-61 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
2,100 MPa305 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
1,850 MPa268 ksi

Elongation at Break

10%
1%

Reduction in Area

24%
35%

Compressive Strength

560 MPa81.2 ksi
2,800 MPa406 ksi

Shear Strength

550 MPa79.8 ksi
470 MPa68.2 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
700 MPa102 ksi

Charpy V-Notch Impact (RT)

8 J5.9 ft·lbf
6 J4.4 ft·lbf

Hardness, Brinell

260 HB
200 HB

Hardness, Rockwell B

101 HRB
93 HRB

Hardness, Vickers

273 HV
700 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

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 1,470°C2,678 °F

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
34 W/m·K19.6 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8.6 % IACS

Electrical Resistivity

2.03×10⁻⁷ Ω·m7.99 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

32 / 100
8 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
5%

Weldability

15 / 100
18 / 100

Formability (cold)

25 / 100
45 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 75 / 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 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 scaleSKS93

SKS93-HR vs SKS93 Q&T 58-61 HRC — frequently asked

Is SKS93 Q&T 58-61 HRC stronger than SKS93-HR?

Yes. SKS93 Q&T 58-61 HRC has a typical yield strength of 1,850 MPa (268 ksi) against 520 MPa (75.4 ksi) for SKS93-HR — about 3.6 times as much. Tensile strength is 2,100 MPa (305 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, HR or Q&T 58-61 HRC?

Annealed is the default SKS93 condition in the FabDigit quote flow (neither HR nor Q&T 58-61 HRC). 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, SKS93-HR or SKS93 Q&T 58-61 HRC?

SKS93-HR. Its machinability rates poor (32/100) against not recommended (8/100) for SKS93 Q&T 58-61 HRC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SKS93-HR and SKS93 Q&T 58-61 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.