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Steel 340X vs S700MC

Steel · grade comparison

Steel 340X and S700MC are both steel grades. S700MC is the stronger of the two: yield strength 740 MPa (107 ksi) against 370 MPa (53.7 ksi) for 340X, about 100% more; tensile strength follows at 810 MPa (117 ksi) vs 450 MPa (65.3 ksi). In exchange, 340X is the more ductile: elongation 26% versus 14% for S700MC, and S700MC is harder (245 HB vs 140 HB). 340X runs hotter in service (350°C vs 300°C continuous) and 340X conducts heat better (48 W/m·K vs 40 W/m·K). On the shop floor, 340X machines more easily (good vs fair) and 340X sits in a lower cost tier (budget, $) than S700MC (standard, $$).

340XChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

S700MCChoose it when strength drives the design.

340X vs S700MC: properties

340XS700MC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

450 MPa65.3 ksi
810 MPa117 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
740 MPa107 ksi

Elongation at Break

26%
14%

Reduction in Area

65%
55%

Compressive Strength

370 MPa53.7 ksi
740 MPa107 ksi

Shear Strength

300 MPa43.5 ksi
490 MPa71.1 ksi

Fatigue Strength (Endurance Limit)

225 MPa32.6 ksi
360 MPa52.2 ksi

Charpy V-Notch Impact (RT)

50 J36.9 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

140 HB
245 HB

Hardness, Rockwell B

76 HRB
100 HRB

Hardness, Vickers

148 HV
255 HV

Hardness, Rockwell C

—
23 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Fracture Toughness (K_IC) 100 MPa·√m91 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,500°C2,732 °F
1,460°C2,660 °F

Liquidus Temperature

1,525°C2,777 °F
1,510°C2,750 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
300°C572 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
8 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

55 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
50%

Weldability

89 / 100
85 / 100

Formability (cold)

74 / 100
65 / 100

Brazeability / Solderability

60 / 100
50 / 100

Polishability

55 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

57 kN·m/kg
103 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

331 kJ/m³
1,304 kJ/m³

Thermal Diffusivity

13 mm²/s
10.8 mm²/s

Thermal Shock Resistance Index

9
13

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 scaleS700MC340X

Manufacturing and finishing

Capability340XS700MC
Sheet metal—Yes
Default condition—TMCP
Relative cost$ Budget$$ Standard
Min. machined wall——
Best machined surface——
Black Oxide—Yes
Cerakote—Yes
Chrome Plating—Yes
E-Coating—Yes
Hot-Dip Galvanizing—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes
Powder Coating—Yes
Tin Plating—Yes
Zinc Plating—Yes
Zinc-Flake (Dip-Spin) Coating—Yes
Zinc-Nickel Plating—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.

340X vs S700MC — frequently asked

Is S700MC stronger than 340X?

Yes. S700MC has a typical yield strength of 740 MPa (107 ksi) against 370 MPa (53.7 ksi) for 340X — about 100% more. Tensile strength is 810 MPa (117 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 340X or S700MC?

340X is the lower-cost material: it sits in the budget tier ($) while S700MC is standard ($$). 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, 340X or S700MC?

340X. Its machinability rates good (55/100) against fair (45/100) for S700MC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 340X and S700MC 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.