Inconel Round Bars
Giriraj Impex is a manufacturer, stockist, supplier and exporter of Inconel round bars in alloys 600, 601, 625 and 718. We manufacture Inconel round bars to ASTM B166 (alloys 600 and 601), ASTM B446 and AMS 5666 (alloy 625), and ASTM B637 and AMS 5662 (alloy 718), in black and bright condition, together with hexagonal and square bars and forged bars, in random lengths or cut to length.
Inconel bars are machined into parts that must stay strong and resist corrosion or oxidation – fasteners, shafts, valve stems and trim, pump parts, forged fittings and flanges, springs and high-temperature fixtures – in oil and gas, chemical, power, marine and aerospace equipment.
Specifications
| Alloy | ASTM / ASME | AMS | Condition |
|---|---|---|---|
| Inconel 600 (N06600) | ASTM B166 / ASME SB166 | – | Annealed or hot finished |
| Inconel 601 (N06601) | ASTM B166 | – | Annealed |
| Inconel 625 (N06625) | ASTM B446 / ASME SB446 | AMS 5666 | Grade 1 annealed or Grade 2 solution annealed |
| Inconel 718 (N07718) | ASTM B637 | AMS 5662 (solution treated), AMS 5663 (aged) | Solution treated, or solution treated and aged |
| Item | Details |
|---|---|
| Shapes | Round, hexagonal, square; forged bars |
| Finish | Black (hot rolled or forged) or bright (peeled, turned, centreless ground) |
| Tolerance | ISO h9, h10, h11 or as ordered for bright bars |
| Optional tests | Ultrasonic test, grain size, hardness, intergranular corrosion |
| Documents | Mill test certificate (MTC); third-party inspection on request |
Composition and properties
| Alloy | Ni | Cr | Fe | Mo | Nb + Ta | C | Mn | Si | S | Other elements |
|---|---|---|---|---|---|---|---|---|---|---|
| 600 (N06600) | 72.0 min | 14.0–17.0 | 6.0–10.0 | – | – | 0.15 | 1.00 | 0.50 | 0.015 | Cu 0.50 |
| 625 (N06625) | 58.0 min | 20.0–23.0 | 5.0 | 8.0–10.0 | 3.15–4.15 | 0.10 | 0.50 | 0.50 | 0.015 | P 0.015, Al 0.40, Ti 0.40, Co 1.0 |
Nickel includes cobalt where stated in the standard. Footnotes as given in each ASTM specification.
| Product | Tensile strength, MPa (ksi) | Yield strength 0.2%, MPa (ksi) | Elongation, % |
|---|---|---|---|
| Plate and sheet – ASTM B443 | 827 (120) | 414 (60) | 30 |
| Pipe and tube – ASTM B444 | 827 (120) | 414 (60) | 30 |
| Bar – ASTM B446 | 827 (120) | 414 (60) | 30 |
Values for Grade 1 annealed material; size limits and Grade 2 (solution annealed) properties as given in each standard.
Alloy 718 composition and properties, including its aged strength, are as given in ASTM B637 and the AMS specification ordered. See also Inconel 625 round bars.
Which Inconel bar for which part
- Inconel 625 – the most widely used Inconel bar for corrosion service: seawater and sour-service fasteners, valve stems, subsea components, pump shafts and fittings machined from bar.
- Inconel 718 – age hardened to very high strength: high-strength bolting, oilfield tool and wellhead components, springs, shafts and turbine parts.
- Inconel 600 – high-temperature parts and fixtures, thermocouple sheaths, and parts exposed to caustic or chlorination environments.
- Inconel 601 – parts exposed to very high temperatures in oxidising atmospheres, such as furnace fixtures and burner components.
Heat treatment of 718 bars
Inconel 718 gets its strength from precipitation hardening. Bars are normally supplied solution treated, which leaves them soft enough to machine; after machining, parts are aged in a two-step treatment to reach full strength. Bars can also be supplied already aged where only light finishing is needed. The ordering specification – for example AMS 5662 for solution treated or AMS 5663 for aged bar, or ASTM B637 with a stated condition – fixes the heat treatment and the properties to be reported.
Manufacturing and quality
Inconel bars are hot rolled or forged from ingot or billet, heat treated, straightened and finished to size. Bright bars are peeled or ground to a close tolerance with a clean surface. Ultrasonic testing confirms internal soundness for critical parts, and grain size is checked where the specification requires. Each bar is marked with alloy, specification, size and heat number. Bars can be supplied to NACE MR0175 / ISO 15156 on request.
Ordering
Please give the alloy and UNS number, specification (ASTM or AMS), condition, shape and size, tolerance, length, quantity and any supplementary tests or inspection.
Machining notes
Inconel alloys work-harden rapidly and keep their strength at the cutting edge, so they need rigid machines, sharp carbide or ceramic tools, positive rake geometries, low cutting speeds and plenty of coolant. Avoid letting tools rub or dwell. Machining solution-treated 718 before ageing is much easier than machining aged material.
Inconel bar for fasteners
Inconel 625 and 718 bars are widely used for bolting in seawater, subsea and sour service, where carbon and low-alloy steel bolts would corrode or crack. Alloy 625 bolting offers excellent corrosion resistance with moderate strength, while age-hardened 718 provides very high strength. For subsea equipment under cathodic protection, hardness and heat treatment limits from the project specification are applied to reduce the risk of hydrogen embrittlement. Fasteners can be supplied finished – see Inconel fasteners – or as bar for machining.
Applications and related products
Inconel round bars are used for Inconel fasteners, valve stems and trim, pump and agitator shafts, subsea and wellhead components, springs, forged and machined pipe fittings and flanges, furnace fixtures and aerospace parts. Thin sizes are supplied as Inconel wires. We also supply Inconel pipes and tubes and Inconel sheets and plates. See all bar materials on the round bars, rods and wires page and alloy guidance on the Inconel page.
Frequently Asked Questions
ASTM B446 (ASME SB446) covers Inconel 625 (UNS N06625) rod and bar. Aerospace bar is commonly supplied to AMS 5666.
ASTM B637 covers Inconel 718 bars and forgings for high-temperature service. AMS 5662 covers solution-treated 718 bar and AMS 5663 covers aged bar.
For parts that need significant machining, solution-treated bar is easier to machine and is aged afterwards. Aged bar is chosen when only light finishing is required.
Grade 1 annealed Inconel 625 bar to ASTM B446 has a minimum tensile strength of 827 MPa (120 ksi) and a minimum 0.2% yield strength of 414 MPa (60 ksi), within the size limits given in the standard.
Yes. Inconel work-hardens quickly and stays strong at the cutting edge, so it needs rigid set-ups, sharp tools, low speeds and good coolant.
Yes. Inconel bars are supplied in round, hexagonal and square shapes, as well as forged bars for larger sections.
Request a Quote for Inconel Round Bars
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Inconel® is a trademark of Special Metals Corporation.