COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF NIMONIC 75 (UNS N06075) FASTENING SYSTEMS
Nimonic 75 (officially designated as UNS N06075 or Alloy 75) is an 80/20 Nickel-Chromium alloy fortified with controlled additions of Titanium and Carbon. Originally developed in the 1940s for the world's first jet engine turbine blades, it remains a foundational superalloy in high-temperature engineering. Its primary attribute is exceptional resistance to oxidation and scaling at elevated temperatures, maintaining surface stability up to 2190°F (1200°C).
While it is a solid-solution strengthened alloy rather than a precipitation-hardened one (like its successor, Nimonic 80A), Nimonic 75 offers excellent high-temperature creep resistance under moderate stresses. It is highly fabricable, readily weldable, and is the definitive fastening choice for sheet-metal combustion chambers, industrial furnace structures, and heat-treatment fixtures where thermal cycling and oxidation are the primary failure mechanisms.
■ Product Overview & Specifications
Nimonic 75 fastening systems are generally supplied in the annealed condition to provide maximum ductility and thermal fatigue resistance during extreme heating and cooling cycles.
| Material Classification | Nickel-Chromium Superalloy (Solid Solution) |
|---|---|
| UNS Designation | N06075 (Alloy 75) |
| Microstructure | Face-Centered Cubic (FCC) Austenitic |
| Magnetic State | Consistently Non-Magnetic |
| Density | ~8.37 g/cm³ (0.302 lb/in³) |
| Melting Point | ~2515°F (1380°C) |
| Size Range | Metric: M6 to M64 | Imperial: 1/4" to 2-1/2" Custom high-temperature threaded rods and furnace pins available. |
| Thread Types | UNC, UNF, Metric Coarse, Metric Fine |
■ Proprietary Datasheet Download (GATED)
Access professional-grade technical data for Nimonic 75, including detailed high-temperature creep-rupture curves, thermal expansion coefficients, and prolonged oxidation weight-loss charts.
Nimonic 75 (N06075) — Complete Technical Datasheet
Contains specific stress-to-rupture thresholds for 1000 and 10,000 hours at temperatures ranging from 600°C to 1000°C, and essential welding/fabrication guidelines.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
To ensure absolute reliability in catastrophic heat environments, Ananka Group provides strict metallurgical certification for all Nimonic 75 fastening packages.
- EN 10204 Type 3.1: Detailed reporting of actual ladle chemical analysis, verifying the crucial 80/20 Nickel-Chromium balance and Titanium additions, along with room-temperature mechanical property verification.
- EN 10204 Type 3.2: Third-party witness testing facilitated for critical aerospace turbine repair packages and high-tier petrochemical processing plants.
■ Chemical Composition (UNS N06075)
The core of Nimonic 75 is an 80% Nickel and 20% Chromium matrix. The Titanium and Carbon additions form titanium carbides, which help pin grain boundaries to provide moderate creep resistance at elevated temperatures.
| Nickel (Ni) | Chromium (Cr) | Titanium (Ti) | Carbon (C) | Iron (Fe) | Manganese (Mn) | Silicon (Si) |
|---|---|---|---|---|---|---|
| Balance (~72 - 76%) | 18.0 – 21.0 | 0.20 – 0.60 | 0.08 – 0.15 | 5.00 Max | 1.00 Max | 1.00 Max |
*Copper (0.50 Max) and Sulfur (0.015 Max) are tightly controlled to prevent hot-shortness and cracking during thermal cycling.
■ Mechanical Properties & Creep Resistance
At room temperature, Nimonic 75 displays moderate strength and high ductility. Its true value is realized at temperatures above 600°C (1110°F), where it resists oxidation scaling and maintains enough tensile strength to support furnace fixtures and exhaust structures.
| Property | Room Temperature (Annealed) | At 1200°F (650°C) |
|---|---|---|
| Tensile Strength (Typical) | 105 ksi (725 MPa) | ~70 ksi (480 MPa) |
| Yield Strength (0.2% Offset) | 45 ksi (310 MPa) | ~30 ksi (205 MPa) |
| Elongation in 2" | 40% | ~40% |
| 10,000-Hour Rupture Stress | N/A | ~20 ksi (138 MPa) |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| UNS Designation | N06075 |
| Common Trade Name | Nimonic 75®, Alloy 75 |
| European Equivalent | W.Nr. 2.4951 / NiCr20Ti |
| British Standard | BS HR5 |
■ Applications & Industries
Nimonic 75 is specifically engineered for environments where oxidation scaling—not extreme multi-ton mechanical stress—is the primary threat to fastener survival.
- Thermal Processing: Heat-treatment furnace fasteners, radiant heater tubes, and high-temperature structural pins.
- Aerospace & Gas Turbines: Fastening systems for combustion chamber sheet metal, exhaust casings, and high-temp brackets.
- Petrochemical: High-temperature gas flaring systems, waste incinerator structural bolting, and exhaust ducting.
- Nuclear Engineering: Specialized structural supports within high-temperature gas-cooled reactors.
■ Compatible Fastener Assemblies
High nickel superalloys are extremely prone to severe thread galling at room temperature during installation, and can cold-weld permanently after heat exposure if not properly mated and lubricated.
| External Threads (Nimonic 75 Studs/Bolts) | Recommended Mating Component (Nuts) |
|---|---|
| Nimonic 75 (Alloy 75) | Nimonic 75 Nuts (Extreme anti-seize lubrication required) |
| Nimonic 75 (Alloy 75) | Nimonic 80A Nuts (Acceptable high-strength pairing) |
■ Torque & Installation Guidelines
Given the moderate yield strength of annealed Nimonic 75, heavy torque loads will cause plastic deformation. Extreme-temperature anti-seize compounds (such as high-purity Nickel paste or Molybdenum Disulfide) are absolutely mandatory to prevent galling during assembly and to ensure the bolts can be removed after extended service at 1000°C.
| Nominal Diameter | Threads Per Inch (UNC) | Target Torque — Lubricated (ft-lbs) |
|---|---|---|
| 3/8" | 16 | 15 - 20 |
| 1/2" | 13 | 35 - 45 |
| 5/8" | 11 | 70 - 90 |
| 3/4" | 10 | 125 - 150 |
■ Why Choose Ananka Group?
Ananka Group operates at the pinnacle of high-temperature superalloy manufacturing, supplying reliable fasteners for the most severe thermal environments.
- Superalloy Machining Experts: Nimonic alloys work-harden rapidly. Our specialized CNC machining utilizes rigid setups, positive rake geometries, and specific feed rates to guarantee pristine thread profiles without work-hardening the root.
- Thread Rolling: We roll internal and external threads whenever feasible to maximize fatigue life and improve galling resistance during high-temperature thermal cycling.
- 100% Traceability: Heat numbers are permanently stamped on every fastener, mapped directly back to premium superalloy mill certificates.
- Custom Furnace Hardware: Manufacturing of engineered furnace pins, custom T-bolts, and high-temperature expansion joint fastening.
■ Frequently Asked Questions
1. What is the difference between Nimonic 75 and Nimonic 80A?
While both share the same 80/20 Nickel-Chromium base, Nimonic 80A contains higher levels of Aluminum and Titanium, allowing it to be "precipitation hardened" (heat treated to extreme strengths). Nimonic 75 is a "solid solution" alloy; it cannot be hardened by heat treatment, making it less strong than 80A but significantly more ductile, weldable, and formable.
2. Is Nimonic 75 primarily used for its strength or its corrosion resistance?
Its primary value is high-temperature oxidation resistance. It prevents the formation of destructive surface scales at temperatures up to 1200°C. While it maintains decent strength (creep resistance) at these temperatures, it is mostly used for sheet structures and furnace parts that simply need to survive the heat without burning away.
3. Can Nimonic 75 be used in cryogenic (sub-zero) applications?
Yes. Because it has a fully austenitic face-centered cubic (FCC) microstructure, it does not suffer from a ductile-to-brittle transition temperature. It remains highly tough and ductile even at cryogenic temperatures, though other alloys are generally preferred for pure cryogenic structural work.
4. Does Nimonic 75 become magnetic at extreme temperatures?
No. Nimonic 75 remains completely non-magnetic from cryogenic temperatures all the way up to its melting point.