Steel 4J50-M vs 4J50-SR
Steel · 4J50 temper comparison
4J50-M and 4J50-SR are two conditions of the same steel grade, 4J50: M (thermomechanically controlled processed) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. 4J50-SR is the stronger of the two: yield strength 400 MPa (58 ksi) against 280 MPa (40.6 ksi) for 4J50-M, about 43% more; tensile strength follows at 580 MPa (84.1 ksi) vs 510 MPa (74 ksi). In exchange, 4J50-M is the more ductile: elongation 35% versus 20% for 4J50-SR, and 4J50-SR is harder (168 HB vs 135 HB). 4J50-M runs hotter in service (500°C vs 450°C continuous).
4J50-MChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
4J50-SRChoose it when strength drives the design.
4J50-M vs 4J50-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
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 150 GPa21.8 Msi · Shear Modulus 58 GPa8.4 Msi · Bulk Modulus 120 GPa17.4 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 8.2 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 13.5 W/m·K7.8 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 9.5 µm/m·K5.3 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -100°C-148 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 4 % IACS · Electrical Resistivity 4.3×10⁻⁷ Ω·m16.9 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Corrosion Resistance 32 / 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 80 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 80 MJ/kg34,394 BTU/lb · Embodied Carbon (primary production) 7 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 20%
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.
4J50-M vs 4J50-SR — frequently asked
Is 4J50-SR stronger than 4J50-M?
Yes. 4J50-SR has a typical yield strength of 400 MPa (58 ksi) against 280 MPa (40.6 ksi) for 4J50-M — about 43% more. Tensile strength is 580 MPa (84.1 ksi) vs 510 MPa (74 ksi).
Which condition does FabDigit quote by default, M or SR?
M is the default 4J50 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 is easier to machine, 4J50-M or 4J50-SR?
4J50-SR, by a small margin. Both rate fair for machinability — 40/100 against 35/100 for 4J50-M.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4J50-M and 4J50-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.