Steel SNCM220 · heat-treated state
Steel SNCM220 Carburized
Properties of the Carburized condition, compared with the other SNCM220 tempers.
The intended service condition: gas-carburized 0.5–1.5 mm case for gear-tooth wear and contact-fatigue resistance with a tough core.
What is SNCM220 Carburized?
SNCM220 Carburized is SNCM220 heat treated to Carburized — the intended service condition: gas-carburized 0.5–1.5 mm case for gear-tooth wear and contact-fatigue resistance with a tough core. SNCM220 Carburized has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 86% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). SNCM220 Carburized 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). HR is the default condition FabDigit quotes; Carburized is available on request or by drawing note.
Advantages
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
Limitations
- Difficult to machine — 12/100, worse than 99% of steel grades
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
SNCM220 Carburized properties
Typical room-temperature values for SNCM220 Carburized — 9 properties are specific to this condition; the rest are grade-level values shared by every SNCM220 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
SNCM220 Carburized 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).
Mechanical14
SNCM220 Carburized has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 86% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SNCM220 Carburized is rated for continuous service to 180°C (356 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
SNCM220 Carburized conducts electricity at 8.5 % IACS, better than 62% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SNCM220 Carburized takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 30%.
Manufacturability7
SNCM220 Carburized's machinability is not recommended (12/100, worse than 99% of steel grades); weldability good (55/100); formability good (60/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other SNCM220 tempers and conditions
SNCM220 is also supplied in 6 other conditions. The full side-by-side table is on the SNCM220 overview.
- HRDefaultDefault stock condition for carburizing-grade bar that will be machined and then case hardened.385 MPa yield · 160 HB
- CarburizedThe intended service condition: gas-carburized 0.5–1.5 mm case for gear-tooth wear and contact-fatigue resistance with a tough core.800 MPa yield · 60 HRC
- Q&TDirect-hardened condition for shafts and fasteners used without carburizing, or as specified core strength after case hardening.720 MPa yield · 29 HRC
- CDPick for straight, size-accurate bright bar for automatic screw-machine work before carburizing.570 MPa yield · 200 HB
- AnnealedUse when maximum softness and machinability or cold forming (cold heading, deep boring) is required before carburizing.385 MPa yield · 149 HB
- NormalizedStandard pre-treatment to refine grain and homogenize structure for uniform case depth and low carburizing distortion.360 MPa yield · 183 HB
Working with SNCM220 Carburized
Is SNCM220 easy to machine?
Machines well in normalized or cold-drawn condition (~65 % of 1212); use carbide, generous coolant and rough before carburizing since the case is only grindable afterwards.
Can SNCM220 be welded?
Weldable with low-hydrogen consumables; preheat 150–250 °C for heavy sections and stress relieve/re-normalize — do not weld carburized surfaces.
Can SNCM220 be formed, bent or molded?
Good cold heading and bending in the annealed state; hot forge 1150–1200 °C and finish above 900 °C, then normalize before machining.
What surface finishes work on SNCM220?
Requires protection — black oxide, phosphate, zinc or oil after carburizing; ground case surfaces polish well but corrode quickly if left bare.
SNCM220 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 | 0.17 – 0.23 | 0.2 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Ni | 0.4 – 0.7 | 0.55 |
| Cr | 0.4 – 0.65 | 0.5 |
| Mo | 0.15 – 0.3 | 0.22 |
| Curesidual, max | ≤ 0.3 | — |
| Fe | balance | — |
SNCM220 Carburized — frequently asked
What is SNCM220 Carburized used for?
SNCM220 Carburized is typically used for gears, industrial drive shafts and pins. In short: carburizing Ni-Cr-Mo bar.
What is the yield strength of SNCM220 Carburized?
SNCM220 Carburized has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is SNCM220 Carburized easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Machines well in normalized or cold-drawn condition (~65 % of 1212); use carbide, generous coolant and rough before carburizing since the case is only grindable afterwards.
Can SNCM220 Carburized be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen consumables; preheat 150–250 °C for heavy sections and stress relieve/re-normalize — do not weld carburized surfaces.
What surface finishes work on SNCM220 Carburized?
Requires protection — black oxide, phosphate, zinc or oil after carburizing; ground case surfaces polish well but corrode quickly if left bare.
Can SNCM220 Carburized be formed, bent or molded?
Good cold heading and bending in the annealed state; hot forge 1150–1200 °C and finish above 900 °C, then normalize before machining.
What is the maximum service temperature of SNCM220 Carburized?
SNCM220 Carburized is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SNCM220-HR and SNCM220-CD?
HR is the default condition — default stock condition for carburizing-grade bar that will be machined and then case hardened. CD: pick for straight, size-accurate bright bar for automatic screw-machine work before carburizing. Yield strength is 385 MPa in HR versus 570 MPa in CD.
Can FabDigit make parts in SNCM220 Carburized?
Yes — SNCM220 Carburized is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4053 — Low-alloyed structural steels for machine structural use — JSA (2016)
- GB/T 3077 — Alloy structural steels (20CrNiMo) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (SAE 8620) — ASM International (1990)
- ASM Machining Data Handbook — ASM International (1980)
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
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.