Steel 4J42 Annealed vs 4J42-HR
Steel · 4J42 temper comparison
4J42 Annealed and 4J42-HR are two conditions of the same steel grade, 4J42: Annealed versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 4J42-HR is the stronger of the two: yield strength 300 MPa (43.5 ksi) against 285 MPa (41.3 ksi) for 4J42 Annealed, about 5% more. In exchange, 4J42 Annealed is the more ductile: elongation 35% versus 30% for 4J42-HR, and 4J42-HR is harder (155 HB vs 145 HB).
4J42 AnnealedChoose it when the part is bent, formed or impact-loaded.
4J42-HRChoose it when strength drives the design.
4J42 Annealed vs 4J42-HR: 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 145 GPa21 Msi · Shear Modulus 57 GPa8.3 Msi · Bulk Modulus 106 GPa15.4 Msi · Poisson's Ratio 0.28
Physical
Density and transition temperatures.
Same in both: Density 8.12 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.
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) 5.3 µm/m·K2.9 µin/in·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.5 % IACS · Electrical Resistivity 7×10⁻⁷ Ω·m27.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.4 V · Corrosion Resistance 28 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Formability (cold)
Same in both: Machinability 35 / 100 · Machinability Rating (AISI 1212 = 100 %) 35% · Weldability 70 / 100 · Brazeability / Solderability 80 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 70 MJ/kg30,095 BTU/lb · Embodied Carbon (primary production) 6.6 kg CO₂/kg · Embodied Water 110 L/kg13.2 gal/lb · Typical Recycled Content 35%
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.
4J42 Annealed vs 4J42-HR — frequently asked
Is 4J42-HR stronger than 4J42 Annealed?
Yes. 4J42-HR has a typical yield strength of 300 MPa (43.5 ksi) against 285 MPa (41.3 ksi) for 4J42 Annealed — about 5% more. Tensile strength is 520 MPa (75.4 ksi) vs 510 MPa (74 ksi).
Which condition does FabDigit quote by default, Annealed or HR?
Annealed is the default 4J42 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.
When should I choose 4J42 Annealed over 4J42-HR?
Pick 4J42 Annealed when the part is bent, formed or impact-loaded. Pick 4J42-HR when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4J42 Annealed and 4J42-HR 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.