Steel 4J42 CR-1/2H vs 4J42-HR
Steel · 4J42 temper comparison
4J42 CR-1/2H and 4J42-HR are two conditions of the same steel grade, 4J42: CR-1/2H (cold Rolled 1/2 Hard) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 4J42 CR-1/2H is the stronger of the two: yield strength 560 MPa (81.2 ksi) against 300 MPa (43.5 ksi) for 4J42-HR, about 87% more; tensile strength follows at 660 MPa (95.7 ksi) vs 520 MPa (75.4 ksi). In exchange, 4J42-HR is the more ductile: elongation 30% versus 10% for 4J42 CR-1/2H, and 4J42 CR-1/2H is harder (208 HB vs 155 HB). 4J42-HR runs hotter in service (400°C vs 280°C continuous).
4J42 CR-1/2HChoose it when strength drives the design.
4J42-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
4J42 CR-1/2H 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.
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 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.
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) 5.3 µm/m·K2.9 µin/in·°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.
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) 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 CR-1/2H vs 4J42-HR — frequently asked
Is 4J42 CR-1/2H stronger than 4J42-HR?
Yes. 4J42 CR-1/2H has a typical yield strength of 560 MPa (81.2 ksi) against 300 MPa (43.5 ksi) for 4J42-HR — about 87% more. Tensile strength is 660 MPa (95.7 ksi) vs 520 MPa (75.4 ksi).
Which condition does FabDigit quote by default, CR-1/2H or HR?
Annealed is the default 4J42 condition in the FabDigit quote flow (neither CR-1/2H nor HR). 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, 4J42 CR-1/2H or 4J42-HR?
4J42 CR-1/2H, by a small margin. Both rate fair for machinability — 42/100 against 35/100 for 4J42-HR; for welding the order is 4J42-HR first (very good, 70/100) then 4J42 CR-1/2H (good, 62/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4J42 CR-1/2H 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.