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Steel A242 vs S355J2W

Steel · grade comparison

Steel A242 and S355J2W are both steel grades. Both yield at about 370 MPa — strength does not separate them. S355J2W runs hotter in service (400°C vs 350°C continuous).

S355J2WChoose it when the part sees heat.

A242 vs S355J2W: properties

A242S355J2W

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
520 MPa75.4 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
380 MPa55.1 ksi

Reduction in Area

50%
55%

Compressive Strength

370 MPa53.7 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
240 MPa34.8 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
110 J81.1 ft·lbf

Hardness, Brinell

155 HB
160 HB

Hardness, Rockwell B

82 HRB
84 HRB

Hardness, Vickers

163 HV
168 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Elongation at Break 24% · Shear Strength 320 MPa46.4 ksi · Fracture Toughness (K_IC) 120 MPa·√m109 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,450°C2,642 °F
1,425°C2,597 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,510°C2,750 °F

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
260 J/g112 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8 % IACS

Electrical Resistivity

2×10⁻⁷ Ω·m7.87 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.58 V

Corrosion Resistance

35 / 100
30 / 100

Manufacturability

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

Machinability

58 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
58%

Formability (cold)

65 / 100
70 / 100

Brazeability / Solderability

40 / 100
55 / 100

Polishability

40 / 100
50 / 100

Castability

—
40 / 100

Same in both: Weldability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.1 kg CO₂/kg

Typical Recycled Content

30%
25%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
66 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

342 kJ/m³
344 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 scaleA242S355J2W

Manufacturing and finishing

CapabilityA242S355J2W
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 S355J2W — frequently asked

What is the difference between A242 and S355J2W?

Steel A242 and S355J2W are both steel grades. Both yield at about 370 MPa — strength does not separate them. S355J2W runs hotter in service (400°C vs 350°C continuous).

Which is cheaper, A242 or S355J2W?

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.

When should I choose A242 over S355J2W?

Pick S355J2W when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A242 and S355J2W 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.