Steel 30NCD16-QT1230
Heat-treated state · default condition
EN 30NCD16
QT1230 = q&T 1230–1420 MPa
Most widely stocked balance of strength and toughness for landing-gear and highly stressed structure.
Values for the QT1230 condition
Other 30NCD16 tempers and conditions
30NCD16 is listed in 8 conditions; see the grade overview at 30NCD16.
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 |
QT1230DefaultThis page 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-QT1230?
30NCD16-QT1230 is 30NCD16 heat treated to QT1230 — most widely stocked balance of strength and toughness for landing-gear and highly stressed structure. 30NCD16-QT1230 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). 30NCD16-QT1230 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).
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-QT1230 properties
Typical room-temperature values for 30NCD16-QT1230; 15 are specific to this condition. Other listed values are 30NCD16 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
30NCD16-QT1230 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-QT1230 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-QT1230 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-QT1230 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-QT1230 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-QT1230'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. Confirm any required mill or lot documentation when quoting.
Working with 30NCD16-QT1230
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.
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.
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 | — |
30NCD16-QT1230 — frequently asked
What is 30NCD16-QT1230 used for?
30NCD16-QT1230 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-QT1230?
30NCD16-QT1230 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-QT1230 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-QT1230 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-QT1230?
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-QT1230 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-QT1230?
30NCD16-QT1230 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.