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Steel SKH51 vs T8

Steel · grade comparison

Steel SKH51 and T8 are both steel grades. T8 is the stronger of the two: tensile strength 900 MPa (131 ksi) against 850 MPa (123 ksi) for SKH51, about 6% more. In exchange, SKH51 is the more ductile: elongation 20% versus 15% for T8. SKH51 is lighter (8.16 g/cm³ vs 8.6 g/cm³ for T8).

SKH51Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

T8Choose it when strength drives the design.

SKH51 vs T8: properties

SKH51T8

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

217 GPa31.5 Msi
220 GPa31.9 Msi

Shear Modulus

84 GPa12.2 Msi
85 GPa12.3 Msi

Bulk Modulus

160 GPa23.2 Msi
170 GPa24.7 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

850 MPa123 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
570 MPa82.7 ksi

Elongation at Break

20%
15%

Reduction in Area

35%
25%

Compressive Strength

900 MPa131 ksi
1,200 MPa174 ksi

Shear Strength

560 MPa81.2 ksi
—

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
—

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
—

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
25 J18.4 ft·lbf

Hardness, Rockwell C

22 HRC
—

Same in both: Hardness, Brinell 240 HB · Hardness, Rockwell B 99 HRB · Hardness, Vickers 250 HV

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,370°C2,498 °F
1,400°C2,552 °F

Liquidus Temperature

1,450°C2,642 °F
1,460°C2,660 °F

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

11 µm/m·K6.1 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F

Min Service Temperature

-60°C-76 °F
-40°C-40 °F

Same in both: Thermal Conductivity 22 W/m·K12.7 BTU/hr·ft·°F · Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
3.1 % IACS

Electrical Resistivity

5.9×10⁻⁷ Ω·m23.2 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

16 / 100
18 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.6 V

Manufacturability

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

Machinability

30 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
40%

Weldability

20 / 100
15 / 100

Formability (cold)

15 / 100
12 / 100

Castability

25 / 100
—

Same in both: Brazeability / Solderability 55 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

45 MJ/kg19,347 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

70 L/kg8.4 gal/lb
90 L/kg10.8 gal/lb

Typical Recycled Content

45%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

104 kN·m/kg
105 kN·m/kg

Specific Stiffness (E / density)

26.6 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

697 kJ/m³
738 kJ/m³

Thermal Diffusivity

6.4 mm²/s
6.1 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleT8SKH51

Manufacturing and finishing

CapabilitySKH51T8
CNC machining—Yes
Default condition—Annealed
Relative cost$$$ Premium$$$ 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.

SKH51 vs T8 — frequently asked

Is T8 stronger than SKH51?

Yes. T8 has a typical tensile strength of 900 MPa (131 ksi) against 850 MPa (123 ksi) for SKH51 — about 6% more.

Which is cheaper, SKH51 or T8?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, SKH51 or T8?

T8. Its machinability rates fair (35/100) against poor (30/100) for SKH51; for welding the order is SKH51 first (poor, 20/100) then T8 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SKH51 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.