Steel SNC815
JIS SNC815
SNC815 is a higher-alloy nickel-chromium case-hardening steel (JIS G 4102, comparable to AISI 3310) with enough nickel to harden a deep case while keeping a tough core.
Reference datasheet — SNC815 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
SNC815 tempers and conditions
SNC815 is supplied in 6 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard stock condition: softest, most machinable state for gear blanking prior to carburizing. | 450 | 700 | 22 | 14 HRC | 34 W/m·K |
Hot rolled | Cheapest mill condition for large forging/machining blanks that will be normalized or annealed before carburizing. | 540 | 830 | 17 | 23 HRC | 33 W/m·K |
Normalized | Grain refinement and structure homogenisation of forgings before carburizing; also used to stabilise machining distortion. | 620 | 900 | 18 | 26 HRC | 33 W/m·K |
Cold drawn | Bright, close-tolerance small-diameter bar for shafts and pinions machined with minimal stock removal. | 690 | 830 | 12 | 23 HRC | 33 W/m·K |
Quenched and tempered | Direct-hardened condition (no carburizing) or the reference core property set used for JIS acceptance testing. | 930 | 1,150 | 14 | 37 HRC | — |
Carburized and hardened | Final service condition for gears and pinions: hard wear-resistant case over a tough, high-hardenability Ni-Cr core. | 1,000 | 1,250 | 12 | 61 HRC | — |
What is SNC815?
SNC815 is a higher-alloy nickel-chromium case-hardening steel (JIS G 4102, comparable to AISI 3310) with enough nickel to harden a deep case while keeping a tough core. It is specified for demanding gear and aerospace-type components and is stocked as hot-rolled, annealed, normalized, cold-drawn, quenched-and-tempered and carburized bar and forging stock. Default properties are 450 MPa yield, 700 MPa tensile, 22 % elongation and 200 HB, with a machinability score of 45 — lower than SNC415 because the high-Ni matrix is gummy and work-hardens. Weldability is poor and there is no corrosion resistance; SNCM420 is the usual alternative when Mo-bearing hardenability is preferred. SNC815 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). SNC815 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 22% and the elastic modulus is 205 GPa (29.7 Msi).
What is SNC815 used for?
- Heavy-duty gears
- Aircraft gearbox components
- Pinion and bull gears
- Highly loaded drive shafts
- Splined couplings
- Bearing races and rollers
- Marine reduction gearing
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
SNC815 properties
Typical room-temperature values for SNC815-A; bars are the position among steel grades.
Physical3
SNC815 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).
Mechanical17
SNC815 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 22% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SNC815 is rated for continuous service to 250°C (482 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
SNC815 conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of SNC815 takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
SNC815's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (35/100); formability fair (50/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. SNC815 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SNC815
Is SNC815 easy to machine?
Machine in the annealed/spheroidized state with sharp coated carbide, moderate speed and heavy flood coolant; the high-Ni matrix is gummy and work-hardens, so avoid dwelling and finish-grind after carburizing.
Can SNC815 be welded?
Poor weldability due to high hardenability — if unavoidable use low-hydrogen or matching Ni filler with 200–300 °C preheat and immediate post-weld temper; never weld carburized surfaces.
Can SNC815 be formed, bent or molded?
Hot forge at 1100–1200 °C and normalize afterwards; cold forming is limited to gentle bending of annealed bar.
SNC815 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 |
|---|---|---|
| C | 0.12 – 0.18 | 0.15 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.35 – 0.65 | 0.5 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Ni | 3 – 3.5 | 3.25 |
| Cr | 0.6 – 1 | 0.8 |
| Curesidual, max | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on SNC815?
Protect with oil, phosphate, black oxide or zinc plating; shot-peen carburized gear roots for fatigue life and bake after any electroplating to avoid hydrogen embrittlement.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel SNC815 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 3310
How much does SNC815 cost?
SNC815 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
SNC815 — frequently asked
What is SNC815 used for?
SNC815 is typically used for heavy-duty gears, aircraft gearbox components, pinion and bull gears, highly loaded drive shafts, splined couplings and bearing races and rollers. In short: deep case, tough core; high-nickel carburizing steel; aerospace gear grade.
What is the yield strength of SNC815?
SNC815 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 6 listed tempers.
Is SNC815 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed/spheroidized state with sharp coated carbide, moderate speed and heavy flood coolant; the high-Ni matrix is gummy and work-hardens, so avoid dwelling and finish-grind after carburizing.
Can SNC815 be welded?
With care — weldability is rated fair (35/100). Poor weldability due to high hardenability — if unavoidable use low-hydrogen or matching Ni filler with 200–300 °C preheat and immediate post-weld temper; never weld carburized surfaces.
What surface finishes work on SNC815?
Protect with oil, phosphate, black oxide or zinc plating; shot-peen carburized gear roots for fatigue life and bake after any electroplating to avoid hydrogen embrittlement.
Can SNC815 be formed, bent or molded?
Hot forge at 1100–1200 °C and normalize afterwards; cold forming is limited to gentle bending of annealed bar.
What is the maximum service temperature of SNC815?
SNC815 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SNC815-A and SNC815-CH?
A is the default condition — standard stock condition: softest, most machinable state for gear blanking prior to carburizing. CH: final service condition for gears and pinions: hard wear-resistant case over a tough, high-hardenability Ni-Cr core. Yield strength is 450 MPa in A versus 1,000 MPa in CH.
How much does SNC815 cost?
SNC815 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- JIS G 4053 — Low-alloyed structural steels (Ni-Cr case hardening steels) — JISC (2016)
- SAE J404 / ASTM A29 — Alloy steel bar chemical compositions (E3310) — SAE / ASTM (2020)
- 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)
- MatWeb / JIS-equivalent alloy steel datasheets — MatWeb LLC (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.