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Steel E3404 vs M4

Steel · grade comparison

Steel E3404 and M4 are both steel grades. M4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 310 MPa (45 ksi) for E3404, about 77% more; tensile strength follows at 880 MPa (128 ksi) vs 350 MPa (50.8 ksi). M4 is the more ductile: elongation 12% versus 10% for E3404, and M4 is harder (250 HB vs 180 HB). E3404 is lighter (7.65 g/cm³ vs 7.97 g/cm³ for M4) and M4 is stiffer (217 GPa vs 115 GPa). On the shop floor, E3404 machines more easily (fair vs poor), E3404 welds better (30 vs 15 out of 100), and E3404 sits in a lower cost tier (standard, $$) than M4 (specialty, $$$$$).

E3404Choose it when weight is the constraint, or when the part is machined in volume.

M4Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

E3404 vs M4: properties

E3404M4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

115 GPa16.7 Msi
217 GPa31.5 Msi

Shear Modulus

44 GPa6.4 Msi
84 GPa12.2 Msi

Bulk Modulus

150 GPa21.8 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

350 MPa50.8 ksi
880 MPa128 ksi

Yield Strength (0.2% offset)

310 MPa45 ksi
550 MPa79.8 ksi

Elongation at Break

10%
12%

Shear Strength

260 MPa37.7 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
—

Hardness, Brinell

180 HB
250 HB

Hardness, Rockwell B

89 HRB
—

Hardness, Vickers

190 HV
265 HV

Reduction in Area

—
25%

Compressive Strength

—
1,600 MPa232 ksi

Fracture Toughness (K_IC)

—
22 MPa·√m20 ksi·√in

Hardness, Rockwell C

—
24 HRC

Physical

Density and transition temperatures.

Density

7.65 g/cm³0.28 lb/in³
7.97 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,480°C2,696 °F
1,250°C2,282 °F

Liquidus Temperature

1,510°C2,750 °F
1,420°C2,588 °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

Specific Heat Capacity

480 J/kg·K0.11 BTU/lb·°F
420 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.8 µm/m·K6.6 µin/in·°F
11 µm/m·K6.1 µin/in·°F

Latent Heat of Fusion

260 J/g112 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Same in both: Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.6 % IACS
2.9 % IACS

Electrical Resistivity

4.8×10⁻⁷ Ω·m18.9 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.58 V

Same in both: Corrosion Resistance 18 / 100

Manufacturability

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

Machinability

35 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
25%

Weldability

30 / 100
15 / 100

Formability (cold)

35 / 100
12 / 100

Brazeability / Solderability

30 / 100
45 / 100

Polishability

40 / 100
50 / 100

Castability

—
20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
110 L/kg13.2 gal/lb

Typical Recycled Content

15%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

46 kN·m/kg
110 kN·m/kg

Specific Stiffness (E / density)

15 MN·m/kg
27.2 MN·m/kg

Modulus of Resilience

418 kJ/m³
697 kJ/m³

Thermal Diffusivity

6.5 mm²/s
6.6 mm²/s

Thermal Shock Resistance Index

6
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 scaleM4E3404

Manufacturing and finishing

CapabilityE3404M4
CNC machining—Yes
Default condition—Annealed
Relative cost$$ Standard$$$$$ Specialty
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.

E3404 vs M4 — frequently asked

Is M4 stronger than E3404?

Yes. M4 has a typical yield strength of 550 MPa (79.8 ksi) against 310 MPa (45 ksi) for E3404 — about 77% more. Tensile strength is 880 MPa (128 ksi) vs 350 MPa (50.8 ksi).

Which is cheaper, E3404 or M4?

E3404 is the lower-cost material: it sits in the standard tier ($$) while M4 is specialty ($$$$$). 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, E3404 or M4?

E3404. Its machinability rates fair (35/100) against poor (25/100) for M4; for welding the order is E3404 first (poor, 30/100) then M4 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in E3404 and M4 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.