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Steel SKH59 vs T8

Steel · grade comparison

Steel SKH59 and T8 are both steel grades. SKH59 is the stronger of the two: yield strength 600 MPa (87 ksi) against 570 MPa (82.7 ksi) for T8, about 5% more. In exchange, T8 is the more ductile: elongation 15% versus 12% for SKH59, and SKH59 is harder (255 HB vs 240 HB). SKH59 is lighter (7.98 g/cm³ vs 8.6 g/cm³ for T8) and T8 runs hotter in service (400°C vs 300°C continuous). On the shop floor, T8 machines more easily (fair vs poor) and T8 sits in a lower cost tier (premium, $$$) than SKH59 (high, $$$$).

SKH59Choose it when strength drives the design, or when weight is the constraint.

T8Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SKH59 vs T8: properties

SKH59T8

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

225 GPa32.6 Msi
220 GPa31.9 Msi

Shear Modulus

86 GPa12.5 Msi
85 GPa12.3 Msi

Poisson's Ratio

0.28
0.29

Yield Strength (0.2% offset)

600 MPa87 ksi
570 MPa82.7 ksi

Elongation at Break

12%
15%

Shear Strength

560 MPa81.2 ksi
—

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
—

Fracture Toughness (K_IC)

22 MPa·√m20 ksi·√in
—

Charpy V-Notch Impact (RT)

12 J8.9 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

255 HB
240 HB

Hardness, Rockwell B

101 HRB
99 HRB

Hardness, Rockwell C

25 HRC
—

Hardness, Vickers

270 HV
250 HV

Same in both: Bulk Modulus 170 GPa24.7 Msi · Tensile Strength (Ultimate) 900 MPa131 ksi · Reduction in Area 25% · Compressive Strength 1,200 MPa174 ksi

Physical

Density and transition temperatures.

Density

7.98 g/cm³0.29 lb/in³
8.6 g/cm³0.31 lb/in³

Melting Point (Solidus)

1,290°C2,354 °F
1,400°C2,552 °F

Liquidus Temperature

1,430°C2,606 °F
1,460°C2,660 °F

Thermal

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

Thermal Conductivity

19 W/m·K11 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.6 µm/m·K5.9 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
3.1 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 18 / 100

Manufacturability

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

Machinability

25 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

25%
40%

Formability (cold)

10 / 100
12 / 100

Castability

25 / 100
—

Brazeability / Solderability

60 / 100
55 / 100

Polishability

80 / 100
70 / 100

Same in both: Weldability 15 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Water

120 L/kg14.4 gal/lb
90 L/kg10.8 gal/lb

Typical Recycled Content

25%
35%

Same in both: Embodied Carbon (primary production) 4.2 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

113 kN·m/kg
105 kN·m/kg

Specific Stiffness (E / density)

28.2 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

800 kJ/m³
738 kJ/m³

Thermal Diffusivity

5.7 mm²/s
6.1 mm²/s

Thermal Shock Resistance Index

7
8

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 scaleT8SKH59

Manufacturing and finishing

CapabilitySKH59T8
CNC machining—Yes
Default condition—Annealed
Relative cost$$$$ High$$$ Premium
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

SKH59 vs T8 — frequently asked

Is SKH59 stronger than T8?

Yes. SKH59 has a typical yield strength of 600 MPa (87 ksi) against 570 MPa (82.7 ksi) for T8 — about 5% more. Tensile strength is 900 MPa (131 ksi) vs 900 MPa (131 ksi).

Which is cheaper, SKH59 or T8?

T8 is the lower-cost material: it sits in the premium tier ($$$) while SKH59 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, SKH59 or T8?

T8. Its machinability rates fair (35/100) against poor (25/100) for SKH59.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SKH59 and T8 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.