Steel S355JR-M vs S355JR-SR
Steel · S355JR temper comparison
S355JR-M and S355JR-SR are two conditions of the same steel grade, S355JR: M (thermomechanically controlled processed) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. S355JR-M is the stronger of the two: yield strength 425 MPa (61.6 ksi) against 380 MPa (55.1 ksi) for S355JR-SR, about 12% more. S355JR-M is harder — 165 HB against 152 HB for S355JR-SR — which matters for wear surfaces and threads.
S355JR-MChoose it when strength drives the design, or when surface hardness matters.
S355JR-M vs S355JR-SR: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
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
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · 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 247 J/g106 BTU/lb · Max Service Temperature (continuous) 350°C662 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: 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) 2.1 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.
S355JR-M vs S355JR-SR — frequently asked
Is S355JR-M stronger than S355JR-SR?
Yes. S355JR-M has a typical yield strength of 425 MPa (61.6 ksi) against 380 MPa (55.1 ksi) for S355JR-SR — about 12% more. Tensile strength is 520 MPa (75.4 ksi) vs 530 MPa (76.9 ksi).
Which condition does FabDigit quote by default, M or SR?
AR is the default S355JR condition in the FabDigit quote flow (neither M nor SR). 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.
When should I choose S355JR-M over S355JR-SR?
Pick S355JR-M when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in S355JR-M and S355JR-SR 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.