Steel 16NC6
EN 16NC6
16NC6 is an AFNOR nickel-chromium case-hardening steel close to AISI 5115, carburized to give a hard surface on a tough low-carbon core.
Reference datasheet — 16NC6 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
16NC6 tempers and conditions
16NC6 is supplied in 9 conditions, soft to hard. +A is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Treated to hardness range | Choose when the buyer specifies a narrow delivery hardness band for automatic machining or cold forming lines. | 340 | 540 | 24 | 160 HB | 8 % IACS |
+ADefault Annealed | Standard stock condition for gear-blank machining and cold forming before carburizing. | 350 | 560 | 22 | 170 HB | — |
Treated to ferrite–pearlite structure and hardness range | Delivery condition specified when uniform ferrite-pearlite microstructure is needed for consistent gear-cutting and distortion control. | 380 | 600 | 20 | 180 HB | 8 % IACS |
Hot rolled | Cheapest mill condition for forging stock or parts that will be normalized/annealed before machining. | 390 | 620 | 18 | 11 HRC | 8 % IACS |
Normalized | Used to refine forging grain and give uniform machining structure before carburizing. | 420 | 650 | 19 | 195 HB | — |
Carburized and tempered, core section 16–40 mm | Same case-hardening cycle on heavier sections; lower core strength because of the steel's limited hardenability. | 520 | 830 | 12 | 59 HRC | — |
Cold drawn | Bright, dimensionally accurate bar for pins and shafts machined with minimal stock removal. | 550 | 700 | 11 | 215 HB | — |
Carburized and hardened | Final in-service condition for gears and pins: hard wear-resistant case with a tough, high-strength core in thin sections. | 680 | 950 | 10 | 60 HRC | — |
Q&T 28–34 HRC | Occasional condition for small non-wearing parts needing a tough medium-hard body without a case. | 750 | 950 | 14 | 31 HRC | — |
What is 16NC6?
16NC6 is an AFNOR nickel-chromium case-hardening steel close to AISI 5115, carburized to give a hard surface on a tough low-carbon core. In the annealed condition it is quoted at 350 MPa yield, 560 MPa tensile, 22 % elongation and 170 HB (87 HRB), with machinability 60 and formability 65, so it machines and cold-heads well before heat treatment; bar, wire and cold-drawn stock are the usual forms. Core hardenability is lower than 18NCD6, service temperature is limited to 300 °C and there is no corrosion resistance. Use 20MC5 or 18NCD6 for more heavily loaded gears. 16NC6 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). 16NC6 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is 16NC6 used for?
- gears
- pins
- small shafts
Advantages
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
16NC6 properties
Typical room-temperature values for 16NC6-+A; bars are the position among steel grades.
Physical3
16NC6 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).
Mechanical15
16NC6 has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
16NC6 is rated for continuous service to 300°C (572 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
16NC6 conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 16NC6 takes about 31 MJ of energy and emits 2.2 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
16NC6's machinability is good (60/100, better than 83% of steel grades); weldability good (60/100); formability good (65/100).
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. 16NC6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 16NC6
Is 16NC6 easy to machine?
Machine fully in the annealed or cold-drawn state with carbide or coated HSS at ~60 % of 1212 rates; after carburizing only grinding or hard turning with CBN is practical.
Can 16NC6 be welded?
Weldable before carburizing by MIG/TIG with low-hydrogen filler and 150–250 °C preheat; avoid welding after case hardening because the case will crack.
Can 16NC6 be formed, bent or molded?
Good cold heading and upsetting in the +TH/+A conditions; hot forge 1100–1150 °C and normalize afterwards to refine grain.
16NC6 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 |
|---|---|---|
| CAFNOR designation index | 0.13 – 0.19 | 0.16 |
| Si | 0.15 – 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| NiN6 → ≈1.5 % Ni | 1.2 – 1.6 | 1.4 |
| Cr | 0.8 – 1.1 | 0.95 |
| Moresidual | ≤ 0.1 | 0.03 |
| P | ≤ 0.04 | 0.02 |
| Smax; 0.020–0.035 for machinability grades | ≤ 0.04 | 0.02 |
| Curesidual | ≤ 0.3 | 0.15 |
| Fe | balance |
What surface finishes work on 16NC6?
Not anodizable — protect with oil, manganese phosphate, black oxide or zinc plating (bake to avoid hydrogen embrittlement on hardened parts); case-hardened surfaces polish and grind well.
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 16NC6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 5115
How much does 16NC6 cost?
16NC6 is a budget-cost steel ($), cheaper than about 90% 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.
16NC6 — frequently asked
What is 16NC6 used for?
16NC6 is typically used for gears, pins and small shafts. In short: easy-forming carburizing steel; AISI 5115 equivalent; light-duty gear grade.
What is the yield strength of 16NC6?
16NC6 has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is 16NC6 easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machine fully in the annealed or cold-drawn state with carbide or coated HSS at ~60 % of 1212 rates; after carburizing only grinding or hard turning with CBN is practical.
Can 16NC6 be welded?
Yes — weldability is rated good (60/100). Weldable before carburizing by MIG/TIG with low-hydrogen filler and 150–250 °C preheat; avoid welding after case hardening because the case will crack.
What surface finishes work on 16NC6?
Not anodizable — protect with oil, manganese phosphate, black oxide or zinc plating (bake to avoid hydrogen embrittlement on hardened parts); case-hardened surfaces polish and grind well.
Can 16NC6 be formed, bent or molded?
Good cold heading and upsetting in the +TH/+A conditions; hot forge 1100–1150 °C and normalize afterwards to refine grain.
What is the maximum service temperature of 16NC6?
16NC6 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 16NC6 +A and 16NC6-CH?
+A is the default condition — standard stock condition for gear-blank machining and cold forming before carburizing. CH: final in-service condition for gears and pins: hard wear-resistant case with a tough, high-strength core in thin sections. Yield strength is 350 MPa in +A versus 680 MPa in CH.
How much does 16NC6 cost?
16NC6 is a budget-cost steel ($), cheaper than about 90% 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
- NF A 35-551 — Aciers pour cémentation (16NC6) — AFNOR (1987)
- EN 10084 — Case hardening steels, technical delivery conditions — CEN (2008)
- SAE J404 — Chemical Compositions of SAE Alloy Steels (5115) — SAE International (2009)
- 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; 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.