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Steel SNCM431-HR vs SNCM431-SR

Steel · SNCM431 temper comparison

SNCM431-HR and SNCM431-SR are two conditions of the same steel grade, SNCM431: HR (hot rolled) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. SNCM431-SR is the stronger of the two: yield strength 730 MPa (106 ksi) against 520 MPa (75.4 ksi) for SNCM431-HR, about 40% more; tensile strength follows at 880 MPa (128 ksi) vs 800 MPa (116 ksi). SNCM431-SR is harder — 265 HB against 235 HB for SNCM431-HR — which matters for wear surfaces and threads.

SNCM431-SRChoose it when strength drives the design, or when surface hardness matters.

SNCM431-HR vs SNCM431-SR: properties

SNCM431-HRSNCM431-SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

800 MPa116 ksi
880 MPa128 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
730 MPa106 ksi

Elongation at Break

19%
20%

Reduction in Area

45%
55%

Compressive Strength

540 MPa78.3 ksi
750 MPa109 ksi

Shear Strength

495 MPa71.8 ksi
545 MPa79 ksi

Fatigue Strength (Endurance Limit)

360 MPa52.2 ksi
405 MPa58.7 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

42 J31 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

235 HB
265 HB

Hardness, Rockwell C

21 HRC
26 HRC

Hardness, Vickers

247 HV
279 HV

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

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 1,490°C2,714 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.8 % IACS

Electrical Resistivity

2.15×10⁻⁷ Ω·m8.46 µΩ·in
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

54 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
56%

Weldability

45 / 100
40 / 100

Formability (cold)

35 / 100
28 / 100

Same in both: Castability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scaleSNCM431

SNCM431-HR vs SNCM431-SR — frequently asked

Is SNCM431-SR stronger than SNCM431-HR?

Yes. SNCM431-SR has a typical yield strength of 730 MPa (106 ksi) against 520 MPa (75.4 ksi) for SNCM431-HR — about 40% more. Tensile strength is 880 MPa (128 ksi) vs 800 MPa (116 ksi).

Which condition does FabDigit quote by default, HR or SR?

QT is the default SNCM431 condition in the FabDigit quote flow (neither HR nor SR). 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, SNCM431-HR or SNCM431-SR?

SNCM431-HR. Its weldability rates fair (45/100) against fair (40/100) for SNCM431-SR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SNCM431-HR and SNCM431-SR 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.