Steel 35NCD16-N (Normalized)
Heat-treated state
EN 35NCD16
Intermediate forging/bar condition giving a uniform fine grain before final hardening.
Values for the N condition
Other 35NCD16 tempers and conditions
35NCD16 is listed in 9 conditions; see the grade overview at 35NCD16.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Delivery condition for rough machining and deep forming before the final quench-and-temper cycle. | 600 | 860 | 18 | 23 HRC | — |
NThis page Normalized | Intermediate forging/bar condition giving a uniform fine grain before final hardening. | 800 | 1,050 | 15 | 33 HRC | 6 % IACS |
Q&T 1080–1230 MPa | Toughest quench-and-temper class — pick when impact energy and SCC resistance outrank strength. | 980 | 1,150 | 15 | 36 HRC | — |
Q&T 1230–1420 MPa | General high-strength shafting and structural fittings with good toughness reserve. | 1,130 | 1,320 | 14 | 41 HRC | — |
Q&T 1420–1620 MPa | Balanced class for actuator bodies, torsion bars and heavy sections needing through-hardening. | 1,300 | 1,520 | 13 | 45 HRC | — |
Q&T 1620–1810 MPa | Ultra-high-strength class where damage tolerance is still specified alongside high load capacity. | 1,460 | 1,700 | 12 | 49 HRC | — |
QT1790Default Q&T 1790–1980 MPa | The classic aerospace condition for landing gear legs and pistons — maximum practical strength with acceptable K_IC. | 1,620 | 1,900 | 11 | 53 HRC | — |
Q&T + gas nitrided surface | Choose for sliding/bearing surfaces on gear pistons: hard nitrided case with unchanged Q&T core (nitride below the tempering temperature). | 1,620 | 1,900 | 10 | 53 HRC | 5.7 % IACS |
Q&T 1930–2130 MPa | Peak-strength condition for the most weight-critical parts; toughness and SCC resistance are marginal, shot peening plus strict hydrogen control are mandatory. | 1,700 | 2,000 | 9 | 55 HRC | — |
What is 35NCD16-N?
35NCD16-N is 35NCD16 heat treated to N — intermediate forging/bar condition giving a uniform fine grain before final hardening. 35NCD16-N 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 15% and the elastic modulus is 205 GPa (29.7 Msi). 35NCD16-N 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). QT1790 is the default condition FabDigit quotes; N is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 75/100, better than 94% of steel grades
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Difficult to machine — 35/100, worse than 84% of steel grades
- Low electrical conductivity — 6 % IACS, worse than 78% of steel grades
- Limited formability — 22/100, worse than 76% of steel grades
35NCD16-N properties
Typical room-temperature values for 35NCD16-N; 22 are specific to this condition. Other listed values are 35NCD16 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
35NCD16-N 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
35NCD16-N 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 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
35NCD16-N is rated for continuous service to 350°C (662 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.8 µm/m·K (6.56 µin/in·°F).
Electrical3
35NCD16-N conducts electricity at 6 % IACS, worse than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 35NCD16-N takes about 36 MJ of energy and emits 2.6 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 25%.
Manufacturability7
35NCD16-N's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (30/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 35NCD16-N
Is 35NCD16 easy to machine?
Rough machine in the annealed state (~240 HB); finish at 50+ HRC with rigid setups, coated carbide or CBN, low speed and heavy flood coolant, and avoid grinding burn on final ground diameters.
Can 35NCD16 be welded?
Poor weldability at high strength: only fusion weld before final heat treatment, with 250–350 °C preheat, low-hydrogen consumables and immediate post-weld temper; welded joints are not used in landing-gear primary structure.
Can 35NCD16 be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold forming is impractical except mild straightening in the annealed condition — all shaping is done before quench and temper.
What surface finishes work on 35NCD16?
Shot peen highly stressed surfaces, then cadmium, zinc-nickel or hard-chrome plate with mandatory hydrogen-embrittlement relief bake (190–200 °C, 8–23 h); never leave the steel bare in service.
35NCD16 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 | 0.32 – 0.39 | 0.35 |
| Si | 0.1 – 0.4 | 0.25 |
| Mn | 0.3 – 0.6 | 0.45 |
| Nigives deep hardenability and low-temperature toughness | 3.6 – 4.1 | 3.85 |
| Cr | 1.6 – 2 | 1.8 |
| Mosuppresses temper embrittlement | 0.25 – 0.45 | 0.35 |
| Vresidual | ≤ 0.05 | — |
| Curesidual | ≤ 0.25 | — |
| Paerospace melt limit | ≤ 0.02 | — |
| Saerospace melt limit | ≤ 0.01 | — |
| Fe | balance | — |
35NCD16-N — frequently asked
What is 35NCD16-N used for?
35NCD16-N is typically used for aircraft landing gear, high-strength shafts and aerospace fasteners. In short: above 1900 MPa tensile; landing-gear grade steel; low ductility, no welding.
What is the yield strength of 35NCD16-N?
35NCD16-N 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 9 listed tempers.
Is 35NCD16-N easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Rough machine in the annealed state (~240 HB); finish at 50+ HRC with rigid setups, coated carbide or CBN, low speed and heavy flood coolant, and avoid grinding burn on final ground diameters.
Can 35NCD16-N be welded?
Not readily — weldability is rated poor (30/100). Poor weldability at high strength: only fusion weld before final heat treatment, with 250–350 °C preheat, low-hydrogen consumables and immediate post-weld temper; welded joints are not used in landing-gear primary structure.
What surface finishes work on 35NCD16-N?
Shot peen highly stressed surfaces, then cadmium, zinc-nickel or hard-chrome plate with mandatory hydrogen-embrittlement relief bake (190–200 °C, 8–23 h); never leave the steel bare in service.
Can 35NCD16-N be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold forming is impractical except mild straightening in the annealed condition — all shaping is done before quench and temper.
What is the maximum service temperature of 35NCD16-N?
35NCD16-N 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 35NCD16-QT1790 and 35NCD16-A?
QT1790 is the default condition — the classic aerospace condition for landing gear legs and pistons — maximum practical strength with acceptable K_IC. A: delivery condition for rough machining and deep forming before the final quench-and-temper cycle. Yield strength is 1,620 MPa in QT1790 versus 600 MPa in A.
Sources
- NF A35-565 / AIR 9160 — 35NCD16 aerospace alloy steel — AFNOR / BNAE (1990)
- 35NCD16 high-strength Ni-Cr-Mo steel bar and forging data — Aubert & Duval (2020)
- 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 — 4340 and ultra-high-strength steel allowables (analogous grade) — Battelle/FAA (2023)
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.