Steel GCr15SiMn-HR vs GCr15SiMn-QT61
Steel · GCr15SiMn temper comparison
GCr15SiMn-HR and GCr15SiMn-QT61 are two conditions of the same steel grade, GCr15SiMn: HR (hot rolled) versus QT61 (Q&T 61-64 HRC). The chemistry is identical, so every difference below comes from the condition. GCr15SiMn-QT61 is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 620 MPa (89.9 ksi) for GCr15SiMn-HR, about 3.1 times as much; tensile strength follows at 2,300 MPa (334 ksi) vs 1,050 MPa (152 ksi). In exchange, GCr15SiMn-HR is the more ductile: elongation 10% versus 1% for GCr15SiMn-QT61, and GCr15SiMn-HR is harder (330 HB vs 195 HB). GCr15SiMn-HR runs hotter in service (300°C vs 120°C continuous) and GCr15SiMn-HR conducts heat better (43 W/m·K vs 36 W/m·K). On the shop floor, GCr15SiMn-HR machines more easily (poor vs not recommended).
GCr15SiMn-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
GCr15SiMn-QT61Choose it when strength drives the design.
GCr15SiMn-HR vs GCr15SiMn-QT61: 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 0.3 · Hardness, Rockwell B 92 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.81 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,470°C2,678 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.5 % IACS · Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 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 %)
Weldability
Formability (cold)
Polishability
Same in both: Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb · Typical Recycled Content 25%
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.
GCr15SiMn-HR vs GCr15SiMn-QT61 — frequently asked
Is GCr15SiMn-QT61 stronger than GCr15SiMn-HR?
Yes. GCr15SiMn-QT61 has a typical yield strength of 1,900 MPa (276 ksi) against 620 MPa (89.9 ksi) for GCr15SiMn-HR — about 3.1 times as much. Tensile strength is 2,300 MPa (334 ksi) vs 1,050 MPa (152 ksi).
Which condition does FabDigit quote by default, HR or QT61?
A is the default GCr15SiMn condition in the FabDigit quote flow (neither HR nor QT61). 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, GCr15SiMn-HR or GCr15SiMn-QT61?
GCr15SiMn-HR. Its machinability rates poor (22/100) against not recommended (8/100) for GCr15SiMn-QT61.
Ready to make it?
Upload a CAD file and FabDigit prices the part in GCr15SiMn-HR and GCr15SiMn-QT61 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.