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Steel M33 vs T8

Steel · grade comparison

Steel M33 and T8 are both steel grades. Both yield at about 550 MPa — strength does not separate them. M33 is the more ductile: elongation 20% versus 15% for T8. M33 is lighter (8.03 g/cm³ vs 8.6 g/cm³ for T8) and M33 runs hotter in service (500°C vs 400°C continuous). On the shop floor, T8 sits in a lower cost tier (premium, $$$) than M33 (high, $$$$).

M33Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

T8Choose it when cost is the deciding factor.

M33 vs T8: properties

M33T8

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

215 GPa31.2 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)

880 MPa128 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

32%
25%

Compressive Strength

620 MPa89.9 ksi
1,200 MPa174 ksi

Shear Strength

560 MPa81.2 ksi
—

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
—

Fracture Toughness (K_IC)

40 MPa·√m36.4 ksi·√in
—

Hardness, Rockwell B

100 HRB
99 HRB

Hardness, Vickers

252 HV
250 HV

Same in both: Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf · Hardness, Brinell 240 HB

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,230°C2,246 °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 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)

500°C932 °F
400°C752 °F

Min Service Temperature

-50°C-58 °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

Electrical

Conductivity and insulation.

Electrical Conductivity

3 % IACS
3.1 % IACS

Electrical Resistivity

5.8×10⁻⁷ Ω·m22.8 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.52 V
-0.6 V

Corrosion Resistance

16 / 100
18 / 100

Manufacturability

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

Machinability

38 / 100
35 / 100

Weldability

18 / 100
15 / 100

Formability (cold)

15 / 100
12 / 100

Castability

30 / 100
—

Polishability

78 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 40% · Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

4.6 kg CO₂/kg
4.2 kg CO₂/kg

Same in both: Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
105 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
25.6 MN·m/kg

Modulus of Resilience

703 kJ/m³
738 kJ/m³

Thermal Diffusivity

6.5 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 scaleT8M33

Manufacturing and finishing

CapabilityM33T8
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.

M33 vs T8 — frequently asked

What is the difference between M33 and T8?

Steel M33 and T8 are both steel grades. Both yield at about 550 MPa — strength does not separate them. M33 is the more ductile: elongation 20% versus 15% for T8.

Which is cheaper, M33 or T8?

T8 is the lower-cost material: it sits in the premium tier ($$$) while M33 is high ($$$$). 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 M33 over T8?

Pick M33 when the part is bent, formed or impact-loaded, or when weight is the constraint. Pick T8 when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M33 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.