Steel 3J53-HR vs 3J53 ST+A
Steel · 3J53 temper comparison
3J53-HR and 3J53 ST+A are two conditions of the same steel grade, 3J53: HR (hot rolled) versus ST+A (solution treated and precipitation aged). The chemistry is identical, so every difference below comes from the condition. 3J53 ST+A is the stronger of the two: yield strength 830 MPa (120 ksi) against 400 MPa (58 ksi) for 3J53-HR, about 108% more; tensile strength follows at 1,180 MPa (171 ksi) vs 800 MPa (116 ksi). In exchange, 3J53-HR is the more ductile: elongation 28% versus 15% for 3J53 ST+A, and 3J53-HR is harder (210 HB vs 172 HB). 3J53 ST+A is stiffer (170 GPa vs 155 GPa) and 3J53 ST+A runs hotter in service (200°C vs 150°C continuous).
3J53-HRChoose it when the part is bent, formed or impact-loaded.
3J53 ST+AChoose it when strength drives the design, or when the part sees heat.
3J53-HR vs 3J53 ST+A: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Shear Modulus 63 GPa9.1 Msi · Bulk Modulus 145 GPa21 Msi · Poisson's Ratio 0.31
Physical
Density and transition temperatures.
Same in both: Density 8.14 g/cm³0.29 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 12.6 W/m·K7.3 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 7.9 µm/m·K4.4 µin/in·°F · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.35 V · Corrosion Resistance 40 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 50 / 100 · Brazeability / Solderability 55 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 130 MJ/kg55,890 BTU/lb · Embodied Carbon (primary production) 9 kg CO₂/kg · Embodied Water 220 L/kg26.4 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.
3J53-HR vs 3J53 ST+A — frequently asked
Is 3J53 ST+A stronger than 3J53-HR?
Yes. 3J53 ST+A has a typical yield strength of 830 MPa (120 ksi) against 400 MPa (58 ksi) for 3J53-HR — about 108% more. Tensile strength is 1,180 MPa (171 ksi) vs 800 MPa (116 ksi).
Which condition does FabDigit quote by default, HR or ST+A?
ST is the default 3J53 condition in the FabDigit quote flow (neither HR nor ST+A). 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, 3J53-HR or 3J53 ST+A?
3J53-HR, by a small margin. Both rate poor for machinability — 30/100 against 22/100 for 3J53 ST+A.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 3J53-HR and 3J53 ST+A 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.