Steel SNCM616-A (Solution annealed)
Temper · default condition
JIS SNCM616
Standard stocked condition: soft, uniform structure for rough machining before carburizing and hardening.
Values for the A condition
Other SNCM616 tempers and conditions
SNCM616 is listed in 6 conditions; see the grade overview at SNCM616.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefaultThis page 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-A?
SNCM616-A is SNCM616 in the A temper — standard stocked condition: soft, uniform structure for rough machining before carburizing and hardening. SNCM616-A 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). SNCM616-A 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).
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-A properties
Typical room-temperature values for SNCM616-A; 10 are specific to this condition. Other listed values are SNCM616 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SNCM616-A 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-A 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-A 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-A 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-A 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-A'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. Confirm any required mill or lot documentation when quoting.
Working with SNCM616-A
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.
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.
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 | — |
SNCM616-A — frequently asked
What is SNCM616-A used for?
SNCM616-A 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-A?
SNCM616-A 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-A 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-A 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-A?
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-A 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-A?
SNCM616-A 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.