Steel 4J29-M vs 4J29-SR
Steel · 4J29 temper comparison
4J29-M and 4J29-SR are two conditions of the same steel grade, 4J29: M (thermomechanically controlled processed) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. 4J29-SR is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 345 MPa (50 ksi) for 4J29-M, about 30% more; tensile strength follows at 600 MPa (87 ksi) vs 520 MPa (75.4 ksi). In exchange, 4J29-M is the more ductile: elongation 30% versus 18% for 4J29-SR, and 4J29-SR is harder (185 HB vs 150 HB).
4J29-MChoose it when the part is bent, formed or impact-loaded.
4J29-SRChoose it when strength drives the design.
4J29-M vs 4J29-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.
Elastic (Young's) Modulus
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: Shear Modulus 52 GPa7.5 Msi · Bulk Modulus 126 GPa18.3 Msi · Poisson's Ratio 0.32
Physical
Density and transition temperatures.
Same in both: Density 8.36 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,440°C2,624 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 17 W/m·K9.8 BTU/hr·ft·°F · Specific Heat Capacity 439 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 5.5 µm/m·K3.1 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 450°C842 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 3.5 % IACS · Electrical Resistivity 4.9×10⁻⁷ Ω·m19.3 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.5 V · Corrosion Resistance 25 / 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 85 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 105 MJ/kg45,142 BTU/lb · Embodied Carbon (primary production) 7.5 kg CO₂/kg · Embodied Water 90 L/kg10.8 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.
4J29-M vs 4J29-SR — frequently asked
Is 4J29-SR stronger than 4J29-M?
Yes. 4J29-SR has a typical yield strength of 450 MPa (65.3 ksi) against 345 MPa (50 ksi) for 4J29-M — about 30% more. Tensile strength is 600 MPa (87 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, M or SR?
M is the default 4J29 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, 4J29-M or 4J29-SR?
4J29-M. Its weldability rates very good (75/100) against very good (70/100) for 4J29-SR.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4J29-M and 4J29-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.