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Steel S355J0W +AR vs S355J0W +M

Steel · S355J0W temper comparison

S355J0W +AR and S355J0W +M are two conditions of the same steel grade, S355J0W: +AR (hot rolled) versus +M (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 385 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus thermomechanically controlled processed). S355J0W +AR runs hotter in service (400°C vs 350°C continuous).

S355J0W +ARChoose it when the part sees heat.

S355J0W +AR vs S355J0W +M: properties

S355J0W +ARS355J0W +M

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

530 MPa76.9 ksi
520 MPa75.4 ksi

Yield Strength (0.2% offset)

385 MPa55.8 ksi
405 MPa58.7 ksi

Elongation at Break

25%
26%

Reduction in Area

55%
60%

Compressive Strength

385 MPa55.8 ksi
405 MPa58.7 ksi

Shear Strength

330 MPa47.9 ksi
325 MPa47.1 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
255 MPa37 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
120 J88.5 ft·lbf

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Hardness, Brinell 155 HB · Hardness, Rockwell B 82 HRB · Hardness, Vickers 163 HV

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °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 0°C32 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8 % IACS · Electrical Resistivity 2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 30 / 100

Manufacturability

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

Weldability

78 / 100
84 / 100

Formability (cold)

62 / 100
68 / 100

Same in both: Machinability 52 / 100 · Machinability Rating (AISI 1212 = 100 %) 58% · Brazeability / Solderability 60 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 30%

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 scaleS355J0W

S355J0W +AR vs S355J0W +M — frequently asked

What is the difference between S355J0W +AR and S355J0W +M?

S355J0W +AR and S355J0W +M are two conditions of the same steel grade, S355J0W: +AR (hot rolled) versus +M (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 385 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hot rolled versus thermomechanically controlled processed).

Which condition does FabDigit quote by default, +AR or +M?

+AR is the default S355J0W condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which welds better, S355J0W +AR or S355J0W +M?

S355J0W +M. Its weldability rates very good (84/100) against very good (78/100) for S355J0W +AR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in S355J0W +AR and S355J0W +M 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.