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Steel 15B35-N vs 15B35 QT-33-39HRC

Steel · 15B35 temper comparison

15B35-N and 15B35 QT-33-39HRC are two conditions of the same steel grade, 15B35: N (normalized) versus QT-33-39HRC. The chemistry is identical, so every difference below comes from the condition. 15B35 QT-33-39HRC is the stronger of the two: yield strength 1,070 MPa (155 ksi) against 450 MPa (65.3 ksi) for 15B35-N, about 138% more; tensile strength follows at 1,200 MPa (174 ksi) vs 720 MPa (104 ksi). In exchange, 15B35-N is the more ductile: elongation 18% versus 13% for 15B35 QT-33-39HRC, and 15B35 QT-33-39HRC is harder (331 HB vs 205 HB). 15B35-N runs hotter in service (400°C vs 300°C continuous).

15B35-NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

15B35 QT-33-39HRCChoose it when strength drives the design.

15B35-N vs 15B35 QT-33-39HRC: properties

15B35-N15B35 QT-33-39HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

720 MPa104 ksi
1,200 MPa174 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
1,070 MPa155 ksi

Elongation at Break

18%
13%

Compressive Strength

450 MPa65.3 ksi
620 MPa89.9 ksi

Shear Strength

430 MPa62.4 ksi
720 MPa104 ksi

Fatigue Strength (Endurance Limit)

325 MPa47.1 ksi
540 MPa78.3 ksi

Charpy V-Notch Impact (RT)

28 J20.7 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

205 HB
331 HB

Hardness, Rockwell B

93 HRB
96 HRB

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 · Reduction in Area 45%

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

47 W/m·K27.2 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
300°C572 °F

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

9.7 % IACS
9.5 % IACS

Electrical Resistivity

1.78×10⁻⁷ Ω·m7.01 µΩ·in
1.8×10⁻⁷ Ω·m7.09 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

52 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

45 / 100
40 / 100

Formability (cold)

62 / 100
55 / 100

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale15B35

15B35-N vs 15B35 QT-33-39HRC — frequently asked

Is 15B35 QT-33-39HRC stronger than 15B35-N?

Yes. 15B35 QT-33-39HRC has a typical yield strength of 1,070 MPa (155 ksi) against 450 MPa (65.3 ksi) for 15B35-N — about 138% more. Tensile strength is 1,200 MPa (174 ksi) vs 720 MPa (104 ksi).

Which condition does FabDigit quote by default, N or QT-33-39HRC?

CD is the default 15B35 condition in the FabDigit quote flow (neither N nor QT-33-39HRC). 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-33-39HRC?

15B35-N. Its weldability rates fair (45/100) against fair (40/100) for 15B35 QT-33-39HRC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15B35-N and 15B35 QT-33-39HRC 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.