Steel S35C-QT vs S35C QT 25-30 HRC
Steel · S35C temper comparison
S35C-QT and S35C QT 25-30 HRC are two conditions of the same steel grade, S35C: QT (quenched and tempered) versus QT 25-30 HRC (Q&T to 25–30 HRC). The chemistry is identical, so every difference below comes from the condition. S35C QT 25-30 HRC is the stronger of the two: yield strength 740 MPa (107 ksi) against 420 MPa (60.9 ksi) for S35C-QT, about 76% more; tensile strength follows at 900 MPa (131 ksi) vs 640 MPa (92.8 ksi). In exchange, S35C-QT is the more ductile: elongation 22% versus 17% for S35C QT 25-30 HRC, and S35C QT 25-30 HRC is harder (277 HB vs 195 HB). On the shop floor, S35C-QT welds better (good vs fair).
S35C-QTChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
S35C QT 25-30 HRCChoose it when strength drives the design.
S35C-QT vs S35C QT 25-30 HRC: 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
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
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 · Shear Strength 380 MPa55.1 ksi · Fracture Toughness (K_IC) 55 MPa·√m50.1 ksi·√in
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 50 W/m·K28.9 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Same in both: Formability (cold) 50 / 100 · Brazeability / Solderability 60 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 60 L/kg7.2 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.
S35C-QT vs S35C QT 25-30 HRC — frequently asked
Is S35C QT 25-30 HRC stronger than S35C-QT?
Yes. S35C QT 25-30 HRC has a typical yield strength of 740 MPa (107 ksi) against 420 MPa (60.9 ksi) for S35C-QT — about 76% more. Tensile strength is 900 MPa (131 ksi) vs 640 MPa (92.8 ksi).
Which condition does FabDigit quote by default, QT or QT 25-30 HRC?
N is the default S35C condition in the FabDigit quote flow (neither QT nor QT 25-30 HRC). 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, S35C-QT or S35C QT 25-30 HRC?
S35C-QT. Its machinability rates good (56/100) against fair (47/100) for S35C QT 25-30 HRC; for welding the order is S35C-QT first (good, 55/100) then S35C QT 25-30 HRC (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in S35C-QT and S35C QT 25-30 HRC 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.