Steel 30NCD16
EN 30NCD16
30NCD16 is a French AFNOR high-nickel chromium-molybdenum ultra-high-strength steel, cross-referenced to 4340, available annealed, normalized, in quenched-and-tempered conditions from QT1080 to QT1770 and quenched-tempered-plus-nitrided.
Reference datasheet — 30NCD16 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 QT1230 condition
30NCD16 tempers and conditions
30NCD16 is supplied in 8 conditions, soft to hard. QT1230 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Supply condition for rough machining, deep cold forming and subsequent hardening. | 560 | 820 | 20 | 235 HB | — |
Normalized | Grain-refining intermediate condition for forgings prior to final quench and temper. | 900 | 1,250 | 12 | 39 HRC | 5.9 % IACS |
Q&T 1080–1230 MPa | Toughest structural class — thick landing-gear forgings and shafts where impact and K_IC dominate. | 1,000 | 1,150 | 14 | 36 HRC | — |
Q&T + gas nitrided | Pick for wear surfaces (pistons, rods, gears) where a 0.3–0.6 mm hard case plus tough core is required. | 1,100 | 1,300 | 11 | 41 HRC | 5.7 % IACS |
QT1230Default Q&T 1230–1420 MPa | Most widely stocked balance of strength and toughness for landing-gear and highly stressed structure. | 1,130 | 1,320 | 12 | 41 HRC | — |
Q&T 1420–1620 MPa | Higher strength for weight-critical pins, actuator rods and links where toughness margin is still acceptable. | 1,330 | 1,520 | 10 | 46 HRC | — |
Q&T 1620–1770 MPa | Used where static strength governs; requires strict hydrogen and SCC control. | 1,470 | 1,700 | 9 | 49 HRC | — |
Q&T 1770–1960 MPa | Peak strength class for small highly loaded parts; lowest toughness and highest embrittlement risk. | 1,570 | 1,860 | 8 | 52 HRC | — |
What is 30NCD16?
30NCD16 is a French AFNOR high-nickel chromium-molybdenum ultra-high-strength steel, cross-referenced to 4340, available annealed, normalized, in quenched-and-tempered conditions from QT1080 to QT1770 and quenched-tempered-plus-nitrided. Engineers select it for aerospace landing gear and highly stressed structural parts because of its deep hardenability and toughness at high strength; usual forms are bar, billet and closed-die forgings. Default values are 1130 MPa yield, 1320 MPa tensile, 12 % elongation, 380 HB (41 HRC), service to 350 °C and a machinability score of 38. Weldability is poor and the steel has no corrosion resistance, so plating plus a de-embrittlement bake is mandatory. 30NCD16 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). 30NCD16 has a yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,320 MPa (191 ksi) — stronger than 93% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
What is 30NCD16 used for?
- aircraft landing gear
- high-strength fasteners
- structural forgings
Advantages
- High strength — 1,130 MPa (164 ksi), better than 93% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
- Low electrical conductivity — 5.7 % IACS, worse than 80% of steel grades
- Difficult to machine — 38/100, worse than 80% of steel grades
30NCD16 properties
Typical room-temperature values for 30NCD16-QT1230; bars are the position among steel grades.
Physical3
30NCD16 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
30NCD16 has a yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,320 MPa (191 ksi) — stronger than 93% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
30NCD16 is rated for continuous service to 350°C (662 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
30NCD16 conducts electricity at 5.7 % IACS, worse than 80% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 30NCD16 takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 20%.
Manufacturability7
30NCD16's machinability is fair (38/100, worse than 80% of steel grades); weldability poor (25/100); formability poor (20/100).
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. 30NCD16 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 30NCD16
Is 30NCD16 easy to machine?
Rough machine annealed (~235 HB), finish after Q&T with rigid setups, carbide/coated tools, 60–120 m/min at 40 HRC; grind or use ceramic inserts above 50 HRC.
Can 30NCD16 be welded?
Poor weldability: preheat 250–350 °C, low-hydrogen or TIG filler, immediate post-weld temper below the part's tempering temperature; avoid welding on high-strength tempers.
Can 30NCD16 be formed, bent or molded?
Hot forge 1100–1180 °C with slow cooling and normalize; cold forming only in the annealed condition, bend radii ≥3t.
30NCD16 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 | 0.26 – 0.34 | 0.3 |
| Si | 0.1 – 0.4 | 0.25 |
| Mn | 0.3 – 0.6 | 0.45 |
| Nigives the deep hardenability and low-temperature toughness | 3.6 – 4.2 | 3.9 |
| Cr | 1.6 – 2 | 1.8 |
| Mosuppresses temper embrittlement | 0.25 – 0.45 | 0.35 |
| Paerospace melt, often ≤0.010 | ≤ 0.02 | |
| SVAR/VD grades ≤0.005 | ≤ 0.01 | |
| Cu | ≤ 0.2 | |
| Fe | balance |
What surface finishes work on 30NCD16?
Shot peen highly stressed surfaces, then cadmium/LHE-zinc-nickel plate, hard chrome or HVOF WC on bearing diameters; bake 190–210 °C for ≥23 h after plating to relieve hydrogen.
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 30NCD16 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 4340
How much does 30NCD16 cost?
30NCD16 is a premium-cost steel ($$$), cheaper than about 51% 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.
30NCD16 — frequently asked
What is 30NCD16 used for?
30NCD16 is typically used for aircraft landing gear, high-strength fasteners and structural forgings. In short: aerospace ultra-high-strength steel; 4340-class deep hardenability; poor weldability, needs plating.
What is the yield strength of 30NCD16?
30NCD16 has a typical yield strength of 1,130 MPa (164 ksi) and a tensile strength of 1,320 MPa (191 ksi) — stronger than 93% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 30NCD16 easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Rough machine annealed (~235 HB), finish after Q&T with rigid setups, carbide/coated tools, 60–120 m/min at 40 HRC; grind or use ceramic inserts above 50 HRC.
Can 30NCD16 be welded?
Not readily — weldability is rated poor (25/100). Poor weldability: preheat 250–350 °C, low-hydrogen or TIG filler, immediate post-weld temper below the part's tempering temperature; avoid welding on high-strength tempers.
What surface finishes work on 30NCD16?
Shot peen highly stressed surfaces, then cadmium/LHE-zinc-nickel plate, hard chrome or HVOF WC on bearing diameters; bake 190–210 °C for ≥23 h after plating to relieve hydrogen.
Can 30NCD16 be formed, bent or molded?
Hot forge 1100–1180 °C with slow cooling and normalize; cold forming only in the annealed condition, bend radii ≥3t.
What is the maximum service temperature of 30NCD16?
30NCD16 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 30NCD16-QT1230 and 30NCD16-ANN?
QT1230 is the default condition — most widely stocked balance of strength and toughness for landing-gear and highly stressed structure. ANN: supply condition for rough machining, deep cold forming and subsequent hardening. Yield strength is 1,130 MPa in QT1230 versus 560 MPa in ANN.
How much does 30NCD16 cost?
30NCD16 is a premium-cost steel ($$$), cheaper than about 51% 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 A35-565 / AIR 9160 — 30NCD16 aerospace alloy steel bars and forgings — AFNOR / BNAE (1990)
- 30NCD16 high-strength Ni-Cr-Mo steel datasheet — Aubert & Duval (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- MMPDS-17 (4340 / low-alloy UHS steel chapters) — Battelle/FAA (2022)
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.