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Steel M42 vs M46

Steel · grade comparison

Steel M42 and M46 are both steel grades. M42 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 560 MPa (81.2 ksi) for M46, about 11% more; tensile strength follows at 900 MPa (131 ksi) vs 850 MPa (123 ksi). On the shop floor, M46 sits in a lower cost tier (high, $$$$) than M42 (specialty, $$$$$).

M42Choose it when strength drives the design.

M46Choose it when cost is the deciding factor.

M42 vs M46: properties

M42M46

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

222 GPa32.2 Msi
217 GPa31.5 Msi

Shear Modulus

86 GPa12.5 Msi
84 GPa12.2 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

900 MPa131 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
560 MPa81.2 ksi

Compressive Strength

680 MPa98.6 ksi
900 MPa131 ksi

Shear Strength

545 MPa79 ksi
550 MPa79.8 ksi

Fracture Toughness (K_IC)

33 MPa·√m30 ksi·√in
—

Charpy V-Notch Impact (RT)

9 J6.6 ft·lbf
20 J14.8 ft·lbf

Hardness, Rockwell B

101 HRB
100 HRB

Hardness, Rockwell C

25 HRC
—

Hardness, Vickers

270 HV
268 HV

Same in both: Bulk Modulus 165 GPa23.9 Msi · Elongation at Break 12% · Reduction in Area 20% · Fatigue Strength (Endurance Limit) 400 MPa58 ksi · Hardness, Brinell 255 HB

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,290°C2,354 °F
1,270°C2,318 °F

Liquidus Temperature

1,420°C2,588 °F
1,430°C2,606 °F

Thermal

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

Thermal Conductivity

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

Latent Heat of Fusion

—
250 J/g107 BTU/lb

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.8 µm/m·K6 µin/in·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -60°C-76 °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).

Corrosion Resistance

18 / 100
15 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.55 V

Manufacturability

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

Machinability

38 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
40%

Weldability

20 / 100
15 / 100

Formability (cold)

10 / 100
15 / 100

Castability

20 / 100
25 / 100

Polishability

80 / 100
70 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

4.4 kg CO₂/kg
4.2 kg CO₂/kg

Same in both: Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

113 kN·m/kg
106 kN·m/kg

Specific Stiffness (E / density)

27.8 MN·m/kg
27.1 MN·m/kg

Modulus of Resilience

866 kJ/m³
723 kJ/m³

Thermal Diffusivity

6.6 mm²/s
7.1 mm²/s

Thermal Shock Resistance Index

8
9

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 scaleM42M46

Manufacturing and finishing

CapabilityM42M46
CNC machiningYes—
Default conditionAnnealed—
Relative cost$$$$$ Specialty$$$$ High
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.

M42 vs M46 — frequently asked

Is M42 stronger than M46?

Yes. M42 has a typical yield strength of 620 MPa (89.9 ksi) against 560 MPa (81.2 ksi) for M46 — about 11% more. Tensile strength is 900 MPa (131 ksi) vs 850 MPa (123 ksi).

Which is cheaper, M42 or M46?

M46 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 welds better, M42 or M46?

M42. Its weldability rates poor (20/100) against poor (15/100) for M46.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M42 and M46 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.