Steel SNCM616
JIS SNCM616
SNCM616 is a high-nickel, low-chromium JIS G 4103 nickel-chromium-molybdenum steel with deep hardenability, supplied hot-rolled, annealed, normalized, cold-drawn, quenched and tempered or carburized.
Reference datasheet — SNCM616 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
SNCM616 tempers and conditions
SNCM616 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 stocked condition: soft, uniform structure for rough machining before carburizing and hardening. | 450 | 700 | 20 | 210 HB | — |
Hot rolled | Cheapest mill condition for stock that will be re-heat-treated; hardness too high and variable for finish machining. | 560 | 880 | 15 | 25 HRC | 7 % IACS |
Normalized | Grain refinement before carburizing on heavy forgings; better machined-surface finish than annealed but harder. | 620 | 900 | 17 | 26 HRC | 7 % IACS |
Cold drawn | Small-diameter precision bar with better size tolerance and surface for shafts and pinion blanks. | 660 | 820 | 12 | 23 HRC | 7 % IACS |
Quenched and tempered | Direct hardening without carburizing for high-strength tough shafts and bolting; meets the JIS G4053 test-piece properties. | 1,000 | 1,240 | 16 | 40 HRC | — |
Carburized and hardened | The intended service condition: hard wear-resistant case (58–62 HRC) over a strong tough Ni-Cr-Mo core for heavy-duty gears. | 1,010 | 1,250 | 14 | 60 HRC | — |
What is SNCM616?
SNCM616 is a high-nickel, low-chromium JIS G 4103 nickel-chromium-molybdenum steel with deep hardenability, supplied hot-rolled, annealed, normalized, cold-drawn, quenched and tempered or carburized. It is used for large-diameter forgings such as turbine rotors and generator shafts where hardening must reach well below the surface; default values are 450 MPa yield, 700 MPa tensile, 20% elongation and 210 HB. Weldability is poor because of the high carbon equivalent, corrosion resistance is nil, and both formability (40) and machinability (45) are moderate. SNCM447 is the usual alternative for smaller high-strength sections. SNCM616 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). SNCM616 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 206 GPa (29.9 Msi).
What is SNCM616 used for?
- large forged shafts
- turbine rotors
- heavy machinery shafts
Limitations
- Difficult to weld — 25/100, worse than 77% of steel grades
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades
SNCM616 properties
Typical room-temperature values for SNCM616-A; bars are the position among steel grades.
Physical3
SNCM616 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).
Mechanical13
SNCM616 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 206 GPa (29.9 Msi).
Thermal6
SNCM616 is rated for continuous service to 400°C (752 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
SNCM616 conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of SNCM616 takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability6
SNCM616's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (25/100); formability fair (40/100).
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. SNCM616 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SNCM616
Is SNCM616 easy to machine?
Machine in the annealed/normalized state with rigid setups, sharp carbide or coated carbide and generous coolant; the tough Ni-rich matrix produces stringy chips, and after carburizing only grinding/EDM is practical.
Can SNCM616 be welded?
Poor weldability due to high carbon equivalent — use low-hydrogen consumables, 200–300 °C preheat, controlled interpass and immediate post-weld tempering; avoid welding on carburized surfaces.
Can SNCM616 be formed, bent or molded?
Hot forge at about 1150–1200 °C down to 900 °C followed by slow cooling and normalize+anneal; cold forming is limited to light straightening and thread rolling on soft bar.
SNCM616 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 |
|---|---|---|
| Ccase-hardening carbon level | 0.13 – 0.2 | 0.16 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.8 – 1.2 | 1 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Nigives deep hardenability and core toughness | 2.8 – 3.2 | 3 |
| Cr | 1.4 – 1.8 | 1.6 |
| Mosuppresses temper embrittlement | 0.4 – 0.6 | 0.5 |
| Curesidual, max | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on SNCM616?
Typical finishes are carburize-harden then grind/shot-peen for fatigue, plus black oxide, phosphate or zinc/nickel plating; bake after plating to avoid hydrogen embrittlement in the hardened case.
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
How much does SNCM616 cost?
SNCM616 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.
SNCM616 — frequently asked
What is SNCM616 used for?
SNCM616 is typically used for large forged shafts, turbine rotors and heavy machinery shafts. In short: deep-hardening high-nickel steel; for large-diameter forgings; tough carburized case.
What is the yield strength of SNCM616?
SNCM616 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 SNCM616 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed/normalized state with rigid setups, sharp carbide or coated carbide and generous coolant; the tough Ni-rich matrix produces stringy chips, and after carburizing only grinding/EDM is practical.
Can SNCM616 be welded?
Not readily — weldability is rated poor (25/100). Poor weldability due to high carbon equivalent — use low-hydrogen consumables, 200–300 °C preheat, controlled interpass and immediate post-weld tempering; avoid welding on carburized surfaces.
What surface finishes work on SNCM616?
Typical finishes are carburize-harden then grind/shot-peen for fatigue, plus black oxide, phosphate or zinc/nickel plating; bake after plating to avoid hydrogen embrittlement in the hardened case.
Can SNCM616 be formed, bent or molded?
Hot forge at about 1150–1200 °C down to 900 °C followed by slow cooling and normalize+anneal; cold forming is limited to light straightening and thread rolling on soft bar.
What is the maximum service temperature of SNCM616?
SNCM616 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SNCM616-A and SNCM616-CH?
A is the default condition — standard stocked condition: soft, uniform structure for rough machining before carburizing and hardening. CH: the intended service condition: hard wear-resistant case (58–62 HRC) over a strong tough Ni-Cr-Mo core for heavy-duty gears. Yield strength is 450 MPa in A versus 1,010 MPa in CH.
How much does SNCM616 cost?
SNCM616 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 steels for machine structural use — JSA (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4: Heat Treating (carburizing of Ni-Cr-Mo gear steels) — ASM International (1991)
- ASM Handbook Vol.16: Machining — ASM International (1989)
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.