Steel 15B35-N vs 15B35 QT-25-30HRC
Steel · 15B35 temper comparison
15B35-N and 15B35 QT-25-30HRC are two conditions of the same steel grade, 15B35: N (normalized) versus QT-25-30HRC. The chemistry is identical, so every difference below comes from the condition. 15B35 QT-25-30HRC is the stronger of the two: yield strength 780 MPa (113 ksi) against 450 MPa (65.3 ksi) for 15B35-N, about 73% more; tensile strength follows at 900 MPa (131 ksi) vs 720 MPa (104 ksi). 15B35 QT-25-30HRC is harder — 277 HB against 205 HB for 15B35-N — which matters for wear surfaces and threads. 15B35-N runs hotter in service (400°C vs 350°C continuous).
15B35-NChoose it when the part sees heat.
15B35 QT-25-30HRCChoose it when strength drives the design, or when surface hardness matters.
15B35-N vs 15B35 QT-25-30HRC: 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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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 · Elongation at Break 18%
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 1,495°C2,723 °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 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
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
Formability (cold)
Same in both: 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) 1.9 kg CO₂/kg · Embodied Water 40 L/kg4.8 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.
15B35-N vs 15B35 QT-25-30HRC — frequently asked
Is 15B35 QT-25-30HRC stronger than 15B35-N?
Yes. 15B35 QT-25-30HRC has a typical yield strength of 780 MPa (113 ksi) against 450 MPa (65.3 ksi) for 15B35-N — about 73% more. Tensile strength is 900 MPa (131 ksi) vs 720 MPa (104 ksi).
Which condition does FabDigit quote by default, N or QT-25-30HRC?
CD is the default 15B35 condition in the FabDigit quote flow (neither N nor QT-25-30HRC). 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 welds better, 15B35-N or 15B35 QT-25-30HRC?
15B35-N. Its weldability rates fair (45/100) against fair (40/100) for 15B35 QT-25-30HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 15B35-N and 15B35 QT-25-30HRC 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.