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Steel 15CrMo4 +N vs 15CrMo4 +S

Steel · 15CrMo4 temper comparison

15CrMo4 +N and 15CrMo4 +S are two conditions of the same steel grade, 15CrMo4: +N (normalized) versus +S (treated for high shearability). The chemistry is identical, so every difference below comes from the condition. 15CrMo4 +N is the stronger of the two: yield strength 400 MPa (58 ksi) against 340 MPa (49.3 ksi) for 15CrMo4 +S, about 18% more; tensile strength follows at 620 MPa (89.9 ksi) vs 540 MPa (78.3 ksi). In exchange, 15CrMo4 +S is the more ductile: elongation 23% versus 20% for 15CrMo4 +N, and 15CrMo4 +N is harder (185 HB vs 160 HB).

15CrMo4 +NChoose it when strength drives the design.

15CrMo4 +SChoose it when the part is bent, formed or impact-loaded.

15CrMo4 +N vs 15CrMo4 +S: properties

15CrMo4 +N15CrMo4 +S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
340 MPa49.3 ksi

Elongation at Break

20%
23%

Reduction in Area

53%
58%

Compressive Strength

400 MPa58 ksi
340 MPa49.3 ksi

Shear Strength

372 MPa54 ksi
325 MPa47.1 ksi

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
245 MPa35.5 ksi

Fracture Toughness (K_IC)

58 MPa·√m52.8 ksi·√in
62 MPa·√m56.4 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
68 J50.2 ft·lbf

Hardness, Brinell

185 HB
160 HB

Hardness, Rockwell B

91 HRB
84 HRB

Hardness, Vickers

195 HV
168 HV

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 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

How each material carries heat and how hot it can run.

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % 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

58 / 100
56 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
63%

Weldability

65 / 100
66 / 100

Formability (cold)

58 / 100
68 / 100

Same in both: Brazeability / Solderability 70 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 31 MJ/kg13,328 BTU/lb · Embodied Carbon (primary production) 2.3 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale15CrMo4

15CrMo4 +N vs 15CrMo4 +S — frequently asked

Is 15CrMo4 +N stronger than 15CrMo4 +S?

Yes. 15CrMo4 +N has a typical yield strength of 400 MPa (58 ksi) against 340 MPa (49.3 ksi) for 15CrMo4 +S — about 18% more. Tensile strength is 620 MPa (89.9 ksi) vs 540 MPa (78.3 ksi).

Which condition does FabDigit quote by default, +N or +S?

+A is the default 15CrMo4 condition in the FabDigit quote flow (neither +N nor +S). 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.

When should I choose 15CrMo4 +N over 15CrMo4 +S?

Pick 15CrMo4 +N when strength drives the design. Pick 15CrMo4 +S when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15CrMo4 +N and 15CrMo4 +S 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.