Steel 8630-HR vs 8630 Q&T
Steel · 8630 temper comparison
8630-HR and 8630 Q&T are two conditions of the same steel grade, 8630: HR (hot rolled) versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 8630 Q&T is the stronger of the two: yield strength 860 MPa (125 ksi) against 415 MPa (60.2 ksi) for 8630-HR, about 107% more; tensile strength follows at 1,000 MPa (145 ksi) vs 690 MPa (100 ksi). In exchange, 8630-HR is the more ductile: elongation 22% versus 18% for 8630 Q&T, and 8630 Q&T is harder (293 HB vs 197 HB). On the shop floor, 8630-HR machines more easily (good vs fair).
8630-HRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
8630 Q&TChoose it when strength drives the design.
8630-HR vs 8630 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)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 93 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 43 W/m·K24.8 BTU/hr·ft·°F · Specific Heat Capacity 477 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 · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 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) -0.61 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 40 / 100 · Formability (cold) 40 / 100 · Castability 55 / 100 · Brazeability / Solderability 55 / 100 · Polishability 55 / 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 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.
8630-HR vs 8630 Q&T — frequently asked
Is 8630 Q&T stronger than 8630-HR?
Yes. 8630 Q&T has a typical yield strength of 860 MPa (125 ksi) against 415 MPa (60.2 ksi) for 8630-HR — about 107% more. Tensile strength is 1,000 MPa (145 ksi) vs 690 MPa (100 ksi).
Which condition does FabDigit quote by default, HR or Q&T?
HR is the default 8630 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, 8630-HR or 8630 Q&T?
8630-HR. Its machinability rates good (60/100) against fair (50/100) for 8630 Q&T.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 8630-HR and 8630 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.