Steel Nitralloy N
Nitralloy N is the nickel-bearing member of the US Nitralloy aluminium-chromium-molybdenum nitriding steel family, with nickel added to improve core toughness in heavier sections.
Reference datasheet — Nitralloy N 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 QT30-36HRC condition
Nitralloy N tempers and conditions
Nitralloy N is supplied in 5 conditions, soft to hard. QT30-36HRC is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for deep machining or cold sawing before the customer performs the hardening + nitriding cycle. | 520 | 760 | 24 | 217 HB | — |
Normalized | Pick for uniform grain size and dimensional stability in forgings prior to hardening. | 650 | 900 | 20 | 27 HRC | 5.6 % IACS |
QT30-36HRCDefault oil quenched from ~900 °C, tempered ~600 °C | Standard as-stocked condition: machine to near-net size in this state, then gas nitride without further hardening. | 830 | 1,000 | 18 | 33 HRC | — |
Q&T core plus gas-nitrided case (~0.3–0.6 mm) | Final in-service condition: extreme surface hardness, wear and scuffing resistance with high compressive residual stress; case is thin and cannot be reground much. | 1,100 | 1,250 | 13 | 41 HRC | — |
Hardened + aged | Pick when the maximum core strength of the Ni-Al precipitation reaction is needed, e.g. heavily loaded shafts backing a nitrided case. | 1,140 | 1,300 | 14 | 41 HRC | — |
What is Nitralloy N?
Nitralloy N is the nickel-bearing member of the US Nitralloy aluminium-chromium-molybdenum nitriding steel family, with nickel added to improve core toughness in heavier sections. It is supplied as quenched, tempered and aged bar and forgings for parts that are gas nitrided after finish machining, typically 830 MPa yield, 1000 MPa tensile, 18 % elongation and 311 HB (33 HRC). Welding is not recommended, machinability is moderate to low (score 40), and the core steel has no corrosion resistance of its own. Nitralloy 135 is the alternative when maximum case hardness outweighs core toughness. Nitralloy N has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F). Nitralloy N has a yield strength of 830 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
What is Nitralloy N used for?
- heavy-duty gears
- crankshafts
- aircraft engine components
Advantages
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- High strength — 830 MPa (120 ksi), better than 87% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Difficult to weld — 18/100, worse than 87% of steel grades
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Poor heat conductor — 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades
- Low electrical conductivity — 5.4 % IACS, worse than 81% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
Nitralloy N properties
Typical room-temperature values for Nitralloy N-QT30-36HRC; bars are the position among steel grades.
Physical3
Nitralloy N has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
Nitralloy N has a yield strength of 830 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
Nitralloy N is rated for continuous service to 500°C (932 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
Nitralloy N conducts electricity at 5.4 % IACS, worse than 81% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (16/100), better than 79% of steel grades.
Sustainability4
Producing a kilogram of Nitralloy N takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
Nitralloy N's machinability is fair (40/100, worse than 77% of steel grades); weldability poor (18/100); formability poor (25/100).
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. Nitralloy N is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Nitralloy N
Is Nitralloy N easy to machine?
Machine fully in the Q&T (30–36 HRC) condition with rigid setups, carbide tooling and generous coolant; leave 0.02–0.05 mm grind stock because nitriding grows the part slightly.
Can Nitralloy N be welded?
Not recommended — high Al and Ni promote oxide entrapment and cracking; if unavoidable, preheat 300–350 °C, use matching or low-hydrogen austenitic filler and re-heat-treat before nitriding.
Can Nitralloy N be formed, bent or molded?
Hot forge 1050–1150 °C with slow cooling and a normalize/anneal afterwards; cold forming is impractical at usable hardness levels.
Nitralloy N 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 | 0.2 – 0.27 | 0.24 |
| Mn | 0.4 – 0.7 | 0.55 |
| Si | 0.2 – 0.4 | 0.3 |
| Cr | 1 – 1.3 | 1.15 |
| Nidistinguishes Nitralloy N from 135/135M | 3.25 – 3.75 | 3.5 |
| Mo | 0.2 – 0.3 | 0.25 |
| Alnitride former; some specifications quote 1.10–1.40 | 1 – 1.3 | 1.15 |
| P | ≤ 0.03 | |
| Smax; selenium-bearing free-machining versions exist | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on Nitralloy N?
Stress relieve above the final tempering temperature before nitriding; gas nitride 500–540 °C for 20–90 h, then lap or lightly grind the white layer — chrome or oxide finishes may follow but no anodizing.
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
How much does Nitralloy N cost?
Nitralloy N 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.
Nitralloy N — frequently asked
What is Nitralloy N used for?
Nitralloy N is typically used for heavy-duty gears, crankshafts and aircraft engine components. In short: nickel-toughened Nitralloy variant; heavy-section nitriding grade; best for shock loading.
What is the yield strength of Nitralloy N?
Nitralloy N has a typical yield strength of 830 MPa (120 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 87% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is Nitralloy N easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine fully in the Q&T (30–36 HRC) condition with rigid setups, carbide tooling and generous coolant; leave 0.02–0.05 mm grind stock because nitriding grows the part slightly.
Can Nitralloy N be welded?
Not readily — weldability is rated poor (18/100). Not recommended — high Al and Ni promote oxide entrapment and cracking; if unavoidable, preheat 300–350 °C, use matching or low-hydrogen austenitic filler and re-heat-treat before nitriding.
What surface finishes work on Nitralloy N?
Stress relieve above the final tempering temperature before nitriding; gas nitride 500–540 °C for 20–90 h, then lap or lightly grind the white layer — chrome or oxide finishes may follow but no anodizing.
Can Nitralloy N be formed, bent or molded?
Hot forge 1050–1150 °C with slow cooling and a normalize/anneal afterwards; cold forming is impractical at usable hardness levels.
What is the maximum service temperature of Nitralloy N?
Nitralloy N is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Nitralloy N QT30-36HRC and Nitralloy N-ANN?
QT30-36HRC is the default condition — standard as-stocked condition: machine to near-net size in this state, then gas nitride without further hardening. ANN: pick for deep machining or cold sawing before the customer performs the hardening + nitriding cycle. Yield strength is 830 MPa in QT30-36HRC versus 520 MPa in ANN.
How much does Nitralloy N cost?
Nitralloy N 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
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (nitriding steels) — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals and Processes (nitriding) — ASM International (2013)
- SAE AMS 6475 / SAE nitriding-steel alloy designations (Nitralloy family) — SAE International (2018)
- Machinery's Handbook — machinability ratings of alloy steels — 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.