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Steel SK5 vs T12A

Steel · grade comparison

Steel SK5 and T12A are both steel grades. Both yield at about 400 MPa — strength does not separate them. T12A is the more ductile: elongation 20% versus 12% for SK5. T12A runs hotter in service (400°C vs 350°C continuous). On the shop floor, T12A sits in a lower cost tier (budget, $) than SK5 (standard, $$).

T12AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SK5 vs T12A: properties

SK5T12A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Tensile Strength (Ultimate)

710 MPa103 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
420 MPa60.9 ksi

Elongation at Break

12%
20%

Reduction in Area

20%
40%

Compressive Strength

720 MPa104 ksi
430 MPa62.4 ksi

Shear Strength

460 MPa66.7 ksi
450 MPa65.3 ksi

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
12 J8.9 ft·lbf

Same in both: Poisson's Ratio 0.29 · Fatigue Strength (Endurance Limit) 320 MPa46.4 ksi · Hardness, Brinell 200 HB · Hardness, Rockwell B 93 HRB · Hardness, Vickers 210 HV

Physical

Density and transition temperatures.

Density

7.82 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,425°C2,597 °F
1,300°C2,372 °F

Liquidus Temperature

1,470°C2,678 °F
1,440°C2,624 °F

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
47 W/m·K27.2 BTU/hr·ft·°F

Specific Heat Capacity

475 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
11.8 µm/m·K6.6 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 9.5 % IACS · Electrical Resistivity 1.8×10⁻⁷ Ω·m7.09 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.62 V

Corrosion Resistance

10 / 100
9 / 100

Manufacturability

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

Machinability

36 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
45%

Weldability

18 / 100
12 / 100

Formability (cold)

30 / 100
40 / 100

Castability

30 / 100
—

Brazeability / Solderability

45 / 100
50 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

27 MJ/kg11,608 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Water

45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb

Same in both: Embodied Carbon (primary production) 2.1 kg CO₂/kg · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

91 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

390 kJ/m³
420 kJ/m³

Thermal Diffusivity

12.9 mm²/s
12.7 mm²/s

Same in both: Thermal Shock Resistance Index 14

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 scaleSK5T12A

Manufacturing and finishing

CapabilitySK5T12A
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$ Standard$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

SK5 vs T12A — frequently asked

What is the difference between SK5 and T12A?

Steel SK5 and T12A are both steel grades. Both yield at about 400 MPa — strength does not separate them. T12A is the more ductile: elongation 20% versus 12% for SK5.

Which is cheaper, SK5 or T12A?

T12A is the lower-cost material: it sits in the budget tier ($) while SK5 is standard ($$). 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, SK5 or T12A?

T12A, by a small margin. Both rate fair for machinability — 45/100 against 36/100 for SK5; for welding the order is SK5 first (poor, 18/100) then T12A (not recommended, 12/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SK5 and T12A 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.