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Steel M3-2 vs M42

Steel · grade comparison

Steel M3-2 and M42 are both steel grades. M42 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for M3-2, about 13% more. On the shop floor, M3-2 sits in a lower cost tier (high, $$$$) than M42 (specialty, $$$$$).

M3-2Choose it when cost is the deciding factor.

M42Choose it when strength drives the design.

M3-2 vs M42: properties

M3-2M42

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

213 GPa30.9 Msi
222 GPa32.2 Msi

Shear Modulus

83 GPa12 Msi
86 GPa12.5 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

880 MPa128 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
620 MPa89.9 ksi

Compressive Strength

600 MPa87 ksi
680 MPa98.6 ksi

Shear Strength

560 MPa81.2 ksi
545 MPa79 ksi

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
9 J6.6 ft·lbf

Hardness, Brinell

250 HB
255 HB

Hardness, Rockwell B

102 HRB
101 HRB

Hardness, Vickers

260 HV
270 HV

Fatigue Strength (Endurance Limit)

—
400 MPa58 ksi

Fracture Toughness (K_IC)

—
33 MPa·√m30 ksi·√in

Hardness, Rockwell C

—
25 HRC

Same in both: Bulk Modulus 165 GPa23.9 Msi · Elongation at Break 12% · Reduction in Area 20%

Physical

Density and transition temperatures.

Density

8.15 g/cm³0.29 lb/in³
7.98 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,240°C2,264 °F
1,290°C2,354 °F

Liquidus Temperature

1,425°C2,597 °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

Thermal Expansion (CTE, 20–100 °C)

10.6 µm/m·K5.9 µin/in·°F
10.8 µm/m·K6 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
—

Min Service Temperature

-50°C-58 °F
-60°C-76 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.2 % IACS
3.1 % IACS

Electrical Resistivity

5.4×10⁻⁷ Ω·m21.3 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
18 / 100

Manufacturability

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

Machinability

30 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
42%

Weldability

18 / 100
20 / 100

Formability (cold)

12 / 100
10 / 100

Castability

25 / 100
20 / 100

Polishability

70 / 100
80 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

42 MJ/kg18,057 BTU/lb
62 MJ/kg26,655 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
4.4 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

40%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
113 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
27.8 MN·m/kg

Modulus of Resilience

710 kJ/m³
866 kJ/m³

Thermal Diffusivity

7 mm²/s
6.6 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 scaleM42M3-2

Manufacturing and finishing

CapabilityM3-2M42
CNC machining—Yes
Default condition—Annealed
Relative cost$$$$ High$$$$$ 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.

M3-2 vs M42 — frequently asked

Is M42 stronger than M3-2?

Yes. M42 has a typical yield strength of 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for M3-2 — about 13% more. Tensile strength is 900 MPa (131 ksi) vs 880 MPa (128 ksi).

Which is cheaper, M3-2 or M42?

M3-2 is the lower-cost material: it sits in the high tier ($$$$) while M42 is specialty ($$$$$). 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, M3-2 or M42?

M42. Its machinability rates fair (38/100) against poor (30/100) for M3-2.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M3-2 and M42 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.