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Steel A242 vs S355MC

Steel · grade comparison

Steel A242 and S355MC are both steel grades. S355MC is the stronger of the two: yield strength 400 MPa (58 ksi) against 370 MPa (53.7 ksi) for A242, about 8% more. On the shop floor, S355MC welds better (excellent vs very good) and S355MC forms better (very good vs good).

S355MCChoose it when strength drives the design, or when it will be welded.

A242 vs S355MC: properties

A242S355MC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
210 GPa30.5 Msi

Shear Modulus

79 GPa11.5 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

510 MPa74 ksi
490 MPa71.1 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
400 MPa58 ksi

Elongation at Break

24%
26%

Reduction in Area

50%
60%

Compressive Strength

370 MPa53.7 ksi
400 MPa58 ksi

Shear Strength

320 MPa46.4 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

155 HB
150 HB

Hardness, Rockwell B

82 HRB
80 HRB

Hardness, Vickers

163 HV
158 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,470°C2,678 °F

Liquidus Temperature

1,510°C2,750 °F
1,520°C2,768 °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
45 W/m·K26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Min Service Temperature

-30°C-22 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 350°C662 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
9 % IACS

Electrical Resistivity

2×10⁻⁷ Ω·m7.87 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.65 V

Corrosion Resistance

35 / 100
12 / 100

Manufacturability

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

Machinability

58 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
65%

Weldability

80 / 100
92 / 100

Formability (cold)

65 / 100
82 / 100

Brazeability / Solderability

40 / 100
70 / 100

Polishability

40 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
35 L/kg4.2 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
62 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

342 kJ/m³
381 kJ/m³

Thermal Diffusivity

13 mm²/s
12.2 mm²/s

Thermal Shock Resistance Index

10
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 scaleA242S355MC

Manufacturing and finishing

CapabilityA242S355MC
Default condition——
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

A242 vs S355MC — frequently asked

Is S355MC stronger than A242?

Yes. S355MC has a typical yield strength of 400 MPa (58 ksi) against 370 MPa (53.7 ksi) for A242 — about 8% more. Tensile strength is 490 MPa (71.1 ksi) vs 510 MPa (74 ksi).

Which is cheaper, A242 or S355MC?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, A242 or S355MC?

S355MC. Its weldability rates excellent (92/100) against very good (80/100) for A242.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A242 and S355MC 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.