Steel 42CrMo4-HR vs 42CrMo4 Q&T
Steel · 42CrMo4 temper comparison
42CrMo4-HR and 42CrMo4 Q&T are two conditions of the same steel grade, 42CrMo4: HR (hot rolled) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 42CrMo4 Q&T is the stronger of the two: yield strength 850 MPa (123 ksi) against 550 MPa (79.8 ksi) for 42CrMo4-HR, about 55% more; tensile strength follows at 1,000 MPa (145 ksi) vs 850 MPa (123 ksi). 42CrMo4 Q&T is harder — 300 HB against 245 HB for 42CrMo4-HR — which matters for wear surfaces and threads.
42CrMo4 Q&TChoose it when strength drives the design, or when surface hardness matters.
42CrMo4-HR vs 42CrMo4 Q&T: 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)
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 14%
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 42.6 W/m·K24.6 BTU/hr·ft·°F · Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 35 / 100 · Formability (cold) 35 / 100 · Brazeability / Solderability 50 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%
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.
42CrMo4-HR vs 42CrMo4 Q&T — frequently asked
Is 42CrMo4 Q&T stronger than 42CrMo4-HR?
Yes. 42CrMo4 Q&T has a typical yield strength of 850 MPa (123 ksi) against 550 MPa (79.8 ksi) for 42CrMo4-HR — about 55% more. Tensile strength is 1,000 MPa (145 ksi) vs 850 MPa (123 ksi).
Which condition does FabDigit quote by default, HR or Q&T?
HR is the default 42CrMo4 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, 42CrMo4-HR or 42CrMo4 Q&T?
42CrMo4-HR, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 42CrMo4 Q&T.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 42CrMo4-HR and 42CrMo4 Q&T 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.