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Steel M46 vs T8

Steel · grade comparison

Steel M46 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 M46, about 6% more. T8 is the more ductile: elongation 15% versus 12% for M46, and M46 is harder (255 HB vs 240 HB). M46 is lighter (8 g/cm³ vs 8.6 g/cm³ for T8). On the shop floor, T8 sits in a lower cost tier (premium, $$$) than M46 (high, $$$$).

M46Choose it when weight is the constraint.

T8Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

M46 vs T8: properties

M46T8

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

165 GPa23.9 Msi
170 GPa24.7 Msi

Tensile Strength (Ultimate)

850 MPa123 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

560 MPa81.2 ksi
570 MPa82.7 ksi

Elongation at Break

12%
15%

Reduction in Area

20%
25%

Compressive Strength

900 MPa131 ksi
1,200 MPa174 ksi

Shear Strength

550 MPa79.8 ksi
—

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
—

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

255 HB
240 HB

Hardness, Rockwell B

100 HRB
99 HRB

Hardness, Vickers

268 HV
250 HV

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,270°C2,318 °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

24 W/m·K13.9 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.8 µm/m·K6 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: 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.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.55 V
-0.6 V

Corrosion Resistance

15 / 100
18 / 100

Manufacturability

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

Formability (cold)

15 / 100
12 / 100

Castability

25 / 100
—

Same in both: Machinability 35 / 100 · Machinability Rating (AISI 1212 = 100 %) 40% · Weldability 15 / 100 · Brazeability / Solderability 55 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Typical Recycled Content

30%
35%

Same in both: Embodied Carbon (primary production) 4.2 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

106 kN·m/kg
105 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

723 kJ/m³
738 kJ/m³

Thermal Diffusivity

7.1 mm²/s
6.1 mm²/s

Thermal Shock Resistance Index

9
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 scaleT8M46

Manufacturing and finishing

CapabilityM46T8
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.

M46 vs T8 — frequently asked

Is T8 stronger than M46?

Yes. T8 has a typical tensile strength of 900 MPa (131 ksi) against 850 MPa (123 ksi) for M46 — about 6% more.

Which is cheaper, M46 or T8?

T8 is the lower-cost material: it sits in the premium tier ($$$) while M46 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose M46 over T8?

Pick M46 when weight is the constraint. Pick T8 when strength drives the design, or when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M46 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.