Steel SNCM815-CH vs SNCM815-HR
Steel · SNCM815 temper comparison
SNCM815-CH and SNCM815-HR are two conditions of the same steel grade, SNCM815: CH (carburized and hardened) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. SNCM815-CH is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 800 MPa (116 ksi) for SNCM815-HR, about 31% more; tensile strength follows at 1,250 MPa (181 ksi) vs 1,100 MPa (160 ksi). SNCM815-CH is harder — 380 HB against 340 HB for SNCM815-HR — which matters for wear surfaces and threads. SNCM815-HR runs hotter in service (400°C vs 180°C continuous). On the shop floor, SNCM815-HR machines more easily (poor vs not recommended) and SNCM815-HR welds better (poor vs not recommended).
SNCM815-CHChoose it when strength drives the design, or when surface hardness matters.
SNCM815-HRChoose it when the part sees heat, or when the part is machined in volume.
SNCM815-CH vs SNCM815-HR: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
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 13%
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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.6 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -75°C-103 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 15 / 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 45 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 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.
SNCM815-CH vs SNCM815-HR — frequently asked
Is SNCM815-CH stronger than SNCM815-HR?
Yes. SNCM815-CH has a typical yield strength of 1,050 MPa (152 ksi) against 800 MPa (116 ksi) for SNCM815-HR — about 31% more. Tensile strength is 1,250 MPa (181 ksi) vs 1,100 MPa (160 ksi).
Which condition does FabDigit quote by default, CH or HR?
NT is the default SNCM815 condition in the FabDigit quote flow (neither CH nor HR). 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, SNCM815-CH or SNCM815-HR?
SNCM815-HR. Its machinability rates poor (28/100) against not recommended (8/100) for SNCM815-CH; for welding the order is SNCM815-HR first (poor, 20/100) then SNCM815-CH (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in SNCM815-CH and SNCM815-HR 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.