Steel SNCM415-HR (Hot rolled)
Supply condition
JIS SNCM415
Cheapest mill condition for rough turning of large gear blanks before carburizing.
Values for the HR 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 | — |
HRThis page 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 | — |
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-HR?
SNCM415-HR is SNCM415 supplied in the HR condition — cheapest mill condition for rough turning of large gear blanks before carburizing. SNCM415-HR has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 52% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi). SNCM415-HR 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; HR is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
SNCM415-HR properties
Typical room-temperature values for SNCM415-HR; 23 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-HR 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-HR has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 52% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SNCM415-HR is rated for continuous service to 300°C (572 °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-HR conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of SNCM415-HR 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-HR's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (45/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SNCM415-HR
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-HR — frequently asked
What is SNCM415-HR used for?
SNCM415-HR 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-HR?
SNCM415-HR has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is SNCM415-HR easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% 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-HR be welded?
With care — weldability is rated fair (45/100). 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-HR?
Not anodizable — use phosphate + oil, black oxide, or Zn/Ni plating (bake to avoid hydrogen embrittlement); ground and honed case polishes well.
Can SNCM415-HR 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-HR?
SNCM415-HR is rated for continuous use to about 300°C (572 °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.