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Steel M50 vs SUJ3

Steel · grade comparison

Steel M50 and SUJ3 are both steel grades. M50 is the stronger of the two: yield strength 570 MPa (82.7 ksi) against 400 MPa (58 ksi) for SUJ3, about 43% more; tensile strength follows at 860 MPa (125 ksi) vs 660 MPa (95.7 ksi). In exchange, SUJ3 is the more ductile: elongation 21% versus 12% for M50, and M50 is harder (240 HB vs 195 HB). SUJ3 conducts heat better (44 W/m·K vs 26 W/m·K). On the shop floor, SUJ3 machines more easily (45 vs 35 out of 100) and SUJ3 sits in a lower cost tier (budget, $) than M50 (premium, $$$).

M50Choose it when strength drives the design.

SUJ3Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

M50 vs SUJ3: properties

M50SUJ3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
208 GPa30.2 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

860 MPa125 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

570 MPa82.7 ksi
400 MPa58 ksi

Elongation at Break

12%
21%

Reduction in Area

25%
45%

Compressive Strength

620 MPa89.9 ksi
700 MPa102 ksi

Shear Strength

560 MPa81.2 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
310 MPa45 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
—

Charpy V-Notch Impact (RT)

20 J14.8 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

240 HB
195 HB

Hardness, Rockwell B

99 HRB
92 HRB

Hardness, Rockwell C

22 HRC
—

Hardness, Vickers

250 HV
205 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

8 g/cm³0.29 lb/in³
7.81 g/cm³0.28 lb/in³

Same in both: Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

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

Thermal Conductivity

26 W/m·K15 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.3 µm/m·K6.3 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Min Service Temperature

-73°C-99 °F
-40°C-40 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
8 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

15 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

35 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
40%

Weldability

10 / 100
8 / 100

Formability (cold)

12 / 100
35 / 100

Castability

20 / 100
—

Brazeability / Solderability

30 / 100
40 / 100

Same in both: Polishability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

50 MJ/kg21,496 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

3.6 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

70 L/kg8.4 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

15%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
85 kN·m/kg

Specific Stiffness (E / density)

25.9 MN·m/kg
26.6 MN·m/kg

Modulus of Resilience

785 kJ/m³
385 kJ/m³

Thermal Diffusivity

7.1 mm²/s
12 mm²/s

Thermal Shock Resistance Index

10
12

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 scaleM50SUJ3

Manufacturing and finishing

CapabilityM50SUJ3
CNC machiningYes—
Default conditionAnnealed—
Relative cost$$$ Premium$ Budget
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.

M50 vs SUJ3 — frequently asked

Is M50 stronger than SUJ3?

Yes. M50 has a typical yield strength of 570 MPa (82.7 ksi) against 400 MPa (58 ksi) for SUJ3 — about 43% more. Tensile strength is 860 MPa (125 ksi) vs 660 MPa (95.7 ksi).

Which is cheaper, M50 or SUJ3?

SUJ3 is the lower-cost material: it sits in the budget tier ($) while M50 is premium ($$$). 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, M50 or SUJ3?

SUJ3, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for M50.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M50 and SUJ3 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.