Steel SNCM415-CN (Carbonitrided)
Heat-treated state
JIS SNCM415
Pick for small thin-section gears/pins needing a shallow, very hard, temper-resistant case at lower cost.
Values for the CN condition
Other SNCM415 tempers and conditions
SNCM415 is listed in 8 conditions; see the grade overview at SNCM415.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for cold extrusion / cold heading of gear and shaft preforms and for best tool life in hobbing. | 370 | 590 | 26 | 165 HB | 7.8 % IACS |
ADefault Solution annealed | Standard stock condition: softest, most machinable state for cutting gear teeth prior to carburizing. | 410 | 640 | 23 | 180 HB | — |
Hot rolled | Cheapest mill condition for rough turning of large gear blanks before carburizing. | 450 | 700 | 20 | 14 HRC | 7.5 % IACS |
Normalized | Uniform fine-grain structure for dimensional stability and reduced distortion during later carburizing. | 490 | 720 | 20 | 17 HRC | 7.5 % IACS |
Cold drawn | Bright, close-tolerance bar for small shafts machined with minimal stock removal. | 650 | 780 | 12 | 20 HRC | 7.5 % IACS |
Quenched and tempered | Use when a tough medium-strength part is needed without a hard case (e.g. bolts, non-contact shafts). | 780 | 950 | 17 | 30 HRC | — |
CNThis page Carbonitrided | Pick for small thin-section gears/pins needing a shallow, very hard, temper-resistant case at lower cost. | 820 | 1,050 | 12 | 61 HRC | 7.2 % IACS |
Carburized & Q&T | Standard finished condition for gears and splines: hard wear/pitting-resistant case over a tough core. | 850 | 1,100 | 12 | 60 HRC | — |
What is SNCM415-CN?
SNCM415-CN is SNCM415 heat treated to CN — pick for small thin-section gears/pins needing a shallow, very hard, temper-resistant case at lower cost. SNCM415-CN has a yield strength of 820 MPa (119 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 87% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). SNCM415-CN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). A is the default condition FabDigit quotes; CN is available on request or by drawing note.
Advantages
- High strength — 820 MPa (119 ksi), better than 87% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Difficult to weld — 5/100, worse than 100% of steel grades
- Difficult to machine — 12/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low fracture toughness — 40 MPa·√m (36.4 ksi·√in), worse than 92% of steel grades
SNCM415-CN properties
Typical room-temperature values for SNCM415-CN; 21 are specific to this condition. Other listed values are SNCM415 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SNCM415-CN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
SNCM415-CN has a yield strength of 820 MPa (119 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 87% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SNCM415-CN is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
SNCM415-CN conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of SNCM415-CN takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
SNCM415-CN's machinability is not recommended (12/100, worse than 99% of steel grades); weldability not recommended (5/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SNCM415-CN
Is SNCM415 easy to machine?
Machine soft (160–200 HB annealed) with coated carbide at ~120–180 m/min; leave 0.2–0.4 mm grinding stock for post-carburizing distortion.
Can SNCM415 be welded?
Weldable in the low-carbon uncarburized state with low-hydrogen consumables, 150–250 °C preheat and PWHT; never weld across a carburized case.
Can SNCM415 be formed, bent or molded?
Cold heading/extrusion is practical in spheroidize-annealed condition; hot forge at 1150–950 °C then normalize to refine grain.
What surface finishes work on SNCM415?
Not anodizable — use phosphate + oil, black oxide, or Zn/Ni plating (bake to avoid hydrogen embrittlement); ground and honed case polishes well.
SNCM415 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CJIS G 4103 | 0.13 – 0.18 | 0.16 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Ni | 1.6 – 2 | 1.8 |
| Cr | 0.4 – 0.65 | 0.52 |
| Mo | 0.15 – 0.3 | 0.22 |
| Curesidual limit | ≤ 0.3 | — |
| Fe | balance | — |
SNCM415-CN — frequently asked
What is SNCM415-CN used for?
SNCM415-CN is typically used for precision transmission gears, pinion and layshafts, cold-headed splined shafts, planetary gear carriers, gear pump and motor shafts and universal joint crosses. In short: balanced Ni-Cr-Mo carburizing steel; good cold-heading formability; low-distortion gear grade.
What is the yield strength of SNCM415-CN?
SNCM415-CN has a typical yield strength of 820 MPa (119 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 87% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is SNCM415-CN easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Machine soft (160–200 HB annealed) with coated carbide at ~120–180 m/min; leave 0.2–0.4 mm grinding stock for post-carburizing distortion.
Can SNCM415-CN be welded?
Not readily — weldability is rated not recommended (5/100). Weldable in the low-carbon uncarburized state with low-hydrogen consumables, 150–250 °C preheat and PWHT; never weld across a carburized case.
What surface finishes work on SNCM415-CN?
Not anodizable — use phosphate + oil, black oxide, or Zn/Ni plating (bake to avoid hydrogen embrittlement); ground and honed case polishes well.
Can SNCM415-CN be formed, bent or molded?
Cold heading/extrusion is practical in spheroidize-annealed condition; hot forge at 1150–950 °C then normalize to refine grain.
What is the maximum service temperature of SNCM415-CN?
SNCM415-CN is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SNCM415-A and SNCM415-CN?
A is the default condition — standard stock condition: softest, most machinable state for cutting gear teeth prior to carburizing. CN: pick for small thin-section gears/pins needing a shallow, very hard, temper-resistant case at lower cost. Yield strength is 410 MPa in A versus 820 MPa in CN.
Sources
- JIS G 4103 — Nickel-chromium-molybdenum steels — JSA (2018)
- SAE J404 — Chemical Compositions of SAE Alloy Steels (8617) — SAE International (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals (carburizing) — ASM International (2013)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.