In high-temperature engineering, selecting the right bar stock for bolts, studs, and turbine components is crucial. Gnee Steel supplies high-quality Nimonic 75 and 80A bars, designed for high-stress applications such as aerospace, automotive valves, and power generation.
While both alloys belong to the Nimonic family, their applications are quite distinct. Understanding these differences is key to ensuring component lifespan and safety. As a leader in wholesale supply, we maintain ample inventory to provide your production line with the highest quality heat-treated bars.
Request wholesale prices for Nimonic 75 round bars
Nimonic 75(GH3030) / 80A Alloy Bars
Nimonic 75(GH3030) / 80A Alloy Bars
Nimonic 75 (often used in conjunction with GH3030) and Nimonic 80A are both nickel-chromium heat-resistant alloys, but 80A has higher strength and can be age-hardened, while 75 has better ductility and is easier to weld. 80A is more suitable for load-bearing turbine components with temperatures up to 815°C, while 75 is ideal for sheet metal work and parts requiring formability.
What is NIMONIC 75 material?
NIMONIC 75 alloy is an 80/20 nickel-chromium alloy with added titanium and carbon. This alloy was originally introduced in the 1940s for the manufacture of turbine blades. It is easy to machine and weld, and possesses good corrosion resistance, mechanical properties, and heat resistance.
1. Specification of Nimonic 75 / 80A Round Bar
| Specification | Details |
|---|---|
| Standards | BS HR 5, BS HR 504, DIN 17752, AECMA PrEN2306, AECMA PrEN2307, AECMA PrEN2306, AECMA PrEN2307, AECMA PrEN2402, ISO 9723, ISO 9724, ISO 9725, MSRR 7004 |
| Dimensions | EN, DIN, JIS, ASTM, BS, ASME, AISI |
| Round Bar Size | Diameter: 3 – 800 mm |
| Hex Bar Size | 2 – 100 mm A/F |
| Flat Bar Size | Thickness: 2 – 100 mm / Width: 10 – 500 mm |
| Square Bar Size | 4 – 100 mm |
| Rectangular Bars Size | 33 x 30 mm to 295 x 1066 mm |
| Hollow Bar | 32 mm OD x 16 mm ID to 250 mm OD x 200 mm ID |
| Bars Tolerance | H8, H9, H10, H11, H12, H13, K9, K10, K11, K12 or as per clients' requirements |
| Bars Finish | Black, Bright Polished, Rough Turned, No.4 Finish, Matt Finish, BA Finish |
2. Equivalent Grades of Nimonic 75/80A Alloy Bar
| Standard | Werkstoff Nr. | UNS |
|---|---|---|
| Nimonic 75 | 2.4951 / 2.4630 | N06075 |
| Nimonic 80A | 2.4952 | N07080 |
3. Chemical Composition of Nimonic 75 / 80A Bar
Nimonic 75 Alloy Bar
| Grade | C (%) | Mn (%) | Si (%) | Cu (%) | Fe (%) | Ni (%) | Cr (%) | Ti (%) |
|---|---|---|---|---|---|---|---|---|
| Nimonic 75 | 0.08 – 0.15 | 1.0 max | 1.0 max | 0.5 max | 5.0 max | Balance | 18.0 – 21.0 | 0.2 – 0.6 |
Nimonic 80A Bar
| Grade | Al (%) | B (%) | C (%) | Cr (%) | Co (%) | Cu (%) | Fe (%) | Mn (%) | Ni (%) | P (%) | Si (%) | S (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nimonic 80A | 1.0 – 1.8 | 0.008 max | 0.10 max | 18.0 – 21.0 | 2.0 max | 0.20 max | 3.0 max | 1.0 max | Balance | 0.045 max | 1.0 max | 0.015 max |
3. Mechanical Properties of Nimonic 75 / 80A Bar
Nimonic 75 Rod
| Grade | Density | Melting Point | Tensile Strength | Yield Strength (0.2% Offset) | Elongation |
|---|---|---|---|---|---|
| Nimonic 75 | 8.37 g/cm³ | 1340 – 1380 °C | 104,000 psi | 40,000 psi | 42% |
Nimonic 80A Bar
| Grade | Condition | Ultimate Tensile Strength (MPa) | Yield Strength (MPa) | Elongation on 4D (min) | Hardness (min) |
|---|---|---|---|---|---|
| Nimonic 80A | Solution Annealed & Precipitation Treated (aged) | 994 | 616 | 20% | 300 HV |
Click to download the GH3030 alloy PDF file now
Nimonic 75 vs. Nimonic 80A
Nimonic 75 (GH3030 equivalent)
Strengthening Mechanism: Solid solution strengthening.
Optimal Applications: Structural components, sheet metal parts, and static high-temperature components.
Reasons for Selection: It offers excellent oxidation resistance and superior ductility. It's the preferred choice if ease of machining and welding is a priority at temperatures up to 800°C.
Nimonic 80A (GH4080A equivalent)
Strengthening Mechanism: Precipitation (aging) hardening (through aluminum and titanium).
Optimal Applications: Fastener-level applications, bolts, exhaust valves, and turbine blades.
Reasons for Selection: Nimonic 80A offers high creep resistance and significantly higher mechanical strength than Nimonic 75 at temperatures up to 815°C. It is designed for components that must withstand heavy mechanical loads and not deform over time.
5. Technical specifications and stock availability of Nimonic 75 and Nimonic 80A bars
We provide these materials in various finishes, including Precision Ground, Peeled, and Bright Drawn, all meeting international standards (ASTM B637, BS HR1, etc.).
| Feature | Nimonic 75 | Nimonic 80A |
| Common Use | Furnace parts, Exhaust ducting | Fasteners, Bolts, Valves |
| Max Strength | Moderate | High (Age Hardened) |
| Creep Resistance | Standard | Excellent |
| Supply Form | Hot Rolled / Forged Bars | Heat-Treated Round Bars |
| Certification | MTC 3.1 Included | MTC 3.1 Included |
Contact our professionals to recommend alloys suitable for your project
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅ Over 18 years of export experience, products sold to more than 80 countries
✅ Certified by ISO, SGS, and BV
✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars
✅ Custom processing services available – including cutting, polishing, CNC machining, and packaging
✅ Fast delivery within 7-15 days, supported by global logistics partners
Gnee Steel GH3030 Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Contact us for the latest export price quote for GH3030 Alloy
FAQ
Q1: Which one is better for high-temperature fasteners and bolts?
A: Nimonic 80A is preferred for high-load fasteners. Due to its precipitation-hardening properties (additions of Al and Ti), it provides the necessary High Creep Resistance that prevents bolts from loosening or failing under intense thermal and mechanical stress. Nimonic 75 is generally too soft for high-load bolting.
Q2: Can Nimonic 75 and 80A be welded together?
A: Yes, but it requires specialized welding consumables and post-weld heat treatment (especially for the 80A side) to maintain the strength of the joint. Consult our technical team for a specific welding procedure.
Q3: What diameters do you keep in stock?
A: We stock round bars from 5mm to 250mm. Precision-ground bright bars are available in smaller diameters (h8-h11), while larger diameters are typically supplied as peeled or forged.
Q4: Do you provide materials for automotive exhaust valves?
A: Yes, our Nimonic 80A bars are a standard choice for high-performance engine exhaust valves due to their excellent hot hardness and corrosion resistance.
