Inconel 718 Tube and Alloy 718 Pipe Supplier in USA
Inconel 718 Pipes & Tubes manufactured and supplied by USA Piping Solution is a tensile, fatigue-resistant, fracture toughness, and corrosion-resistant alloy made of nickel-chromium superalloy that is hardened using precipitation in service up to 700 C (1300 F). Inconel 718 (UNS N07718 / DIN 2.4668 / Werkstoff Nr. 2.4668) is the single most widely used superalloy in the world, accounting for approximately half of all superalloy production, and is the standard material for aerospace jet engines, gas turbines, and oil and gas downhole tools.
The exceptional mechanical performance of alloy 718 tube and pipe comes from precipitation hardening by niobium (Nb) and molybdenum (Mo) additions. These form the gamma double prime (γ″) and gamma prime (γ′) precipitate phases within the nickel matrix on ageing heat treatment yielding a minimum tensile strength of 1310 MPa (190 ksi) in the age-hardened condition. Unlike Inconel 625, which relies on solid-solution strengthening, Inconel 718 must be heat-treated to develop its full mechanical properties.
As established Inconel 718 tube suppliers in the USA, we supply Inconel 718 seamless tube (ASTM B163 / AMS 5589), welded tube (ASTM B516 / AMS 5590), seamless pipe (ASTM B670), and welded pipe (ASTM B725) with full EN 10204 3.1/3.2 MTC, AMS traceability, and NADCAP-approved material documentation. Explore our full Inconel Pipes & Tubes and Nickel Alloy Pipes & Tubes range.
USA Piping Solution has supplied certified Inconel 718 pipe and tube to aerospace, oil & gas, and defence customers across the United States for over 40 years with full AMS traceability and NADCAP-approved documentation on every order.
Table of Contents
- Key Characteristics of Inconel 718 Pipe & Tube
- Inconel 718 Pipe & Tube Specifications
- Inconel 718 Equivalent Grades
- Chemical Composition of Inconel 718 Pipes & Tubes
- Mechanical & Physical Properties of Inconel 718
- Inconel 718 Seamless Pipe & Tube Size Chart
- Inconel 718 Welded Pipe & Tube Size Range
- Inconel 718 Pipe Weight Chart
- Types of Inconel 718 Pipes & Tubes
- Service Environment Guidance
- Heat Treatment of Inconel 718 Pipe & Tube
- Welding Inconel 718 Pipe & Alloy 718 Tube
- Key Advantages of Inconel 718 Pipes & Tubes
- Applications of Inconel 718 Pipe & Tube
- Inconel 718 Tube Price
- Related Products
- Frequently Asked Questions
Key Characteristics of Inconel 718 Pipe & Tube
- Excellent tensile, fatigue & fracture resistance
- Creep resistance up to 700°C (1300°F)
- Outstanding corrosion & oxidation resistance
- Resistance to sulfidation & chloride attack
- Good pitting resistance in acids & chlorides
- Readily weldable — good fabricability
- Age-hardenable to 1300+ MPa tensile strength
- Excellent cryogenic toughness (down to −253°C)
- Stable magnetic & surface finish properties
Inconel 718 Pipe & Tube Specifications
Parameter |
Details |
|---|---|
Grade |
Inconel 718 (UNS N07718) |
Standards |
ASTM, ASME, AMS, API |
Seamless Tube |
ASTM B163 / ASME SB163 · AMS 5589 |
Welded Tube |
ASTM B516 / ASME SB516 · AMS 5590 |
Seamless Pipe |
ASTM B670 / ASME SB670 |
Welded Pipe |
ASTM B725 / ASME SB725 · ASTM B730 |
Seamless Pipe NB |
1/4" NB to 6" NB |
Welded/ERW Pipe NB |
1" NB to 16" NB |
Seamless Tube OD |
3.35 mm OD to 101.6 mm OD |
Welded Tube OD |
6.35 mm OD to 152 mm OD |
Wall Thickness ✏ |
0.020" – 0.220" WT (0.508 mm – 5.59 mm); special wall thicknesses on request |
Hardness (aged) ★ |
40–48 HRC (precipitation hardened) |
SWG / BWG |
10, 12, 14, 16, 18, 20 SWG |
Schedule |
SCH 20, 30, 40, STD, 60, 80, XS, 120, 140, 160, XXS |
Length |
Single Random, Double Random, Cut-to-Length (3 m / 6 m standard) |
Type |
Seamless / ERW / Welded / EFW / Fabricated |
Form |
Round, Square, Rectangular, Coil, U-Bend, Hydraulic, Capillary, LSAW |
End |
Plain End, Beveled End, Threaded |
Finish |
Polished · AP (Annealed & Pickled) · BA (Bright Annealed) · MF |
Marking |
Standard, Grade, OD, Thickness, Length, Heat No. (or per customer spec) |
Certification |
EN 10204 3.1 / 3.2 MTC · AMS traceability · NADCAP · PED · DNV · TUV |
Inconel 718 Equivalent Grades
Standard |
UNS |
W.Nr. / DIN |
EN |
JIS |
AMS |
Trade Names |
|---|---|---|---|---|---|---|
Inconel 718 |
N07718 |
2.4668 |
NiCr19Fe19Nb5Mo3 |
NCF 718 |
AMS 5589 / 5590 |
Nicrofer 5219 · Haynes 718 · Pyromet 718 · Superimphy 718 · Udimet 718 |
Chemical Composition of Inconel 718 Pipes & Tubes (UNS N07718)
Niobium (4.75–5.50%) and molybdenum (2.80–3.30%), combined with aluminium and titanium, form the γ″ (gamma double prime) and γ′ (gamma prime) precipitate phases during age hardening — delivering minimum tensile strength of 1310 MPa at temperatures up to 700°C.
|
Element |
Ni |
Cr |
Fe |
Nb + Ta |
Mo |
Ti |
Al |
Co |
C |
Mn |
Si |
Cu |
P |
S |
B |
|
Min (%) |
50.0 |
17.0 |
Bal. |
4.75 |
2.80 |
0.65 |
0.20 |
— |
— |
— |
— |
— |
— |
— |
— |
|
Max (%) |
55.0 |
21.0 |
Bal. |
5.50 |
3.30 |
1.15 |
0.80 |
1.0 |
0.08 |
0.35 |
0.35 |
0.30 |
0.015 |
0.015 |
0.006 |
Mechanical & Physical Properties of Inconel 718
Mechanical Properties
| Condition | Tensile Strength | Yield Strength 0.2% | Elongation | Hardness |
|---|---|---|---|---|
| Annealed (solution) | 965 MPa (140 ksi) | 550 MPa (80 ksi) | 30% | ≤ 36 HRC |
| Precipitation hardened (aged) | 1310 MPa (190 ksi) | 1170 MPa (170 ksi) | 12% | 40–48 HRC |
Physical Properties
| Physical Property | Value |
|---|---|
| Density | 8.19 g/cm³ (0.296 lb/in³) |
| Melting Range | 1260–1336°C (2300–2437°F) |
| Max Service Temperature ✏ | 700°C (1300°F) continuous; short-term excursions to 980°C permissible in annealed condition |
| Modulus of Elasticity (21°C) | 200 GPa (29 × 10⁶ psi) |
| Thermal Expansion (21–538°C) | 13.0 µm/m·°C |
| Thermal Conductivity (21°C) | 11.4 W/m·K |
| Specific Heat (21°C) | 435 J/kg·°C |
| Electrical Resistivity (21°C) | 1.25 µΩ·m |
| Poisson’s Ratio | 0.284 |
Inconel 718 Seamless Pipe & Tube Size Chart
Seamless tube (ASTM B163 / AMS 5589): OD 3.35–101.6 mm. Seamless pipe (ASTM B670): ¼" to 6" NB. Wall thickness in inches.
|
NB Size |
OD (inches) |
SCH 10S |
SCH 40S / Std |
SCH 80S / XH |
SCH 160 |
XXS |
|---|---|---|---|---|---|---|
|
1/4" |
0.540 |
0.065 |
0.088 |
0.119 |
— |
— |
|
3/8" |
0.675 |
0.065 |
0.091 |
0.126 |
— |
— |
|
1/2" |
0.840 |
0.083 |
0.109 |
0.147 |
0.187 |
0.294 |
|
3/4" |
1.050 |
0.083 |
0.113 |
0.154 |
0.219 |
0.308 |
|
1" |
1.315 |
0.109 |
0.133 |
0.179 |
0.250 |
0.358 |
|
1½" |
1.900 |
0.109 |
0.145 |
0.200 |
0.281 |
0.400 |
|
2" |
2.375 |
0.109 |
0.154 |
0.218 |
0.343 |
0.436 |
|
3" |
3.500 |
0.120 |
0.216 |
0.300 |
0.438 |
0.600 |
|
4" |
4.500 |
0.120 |
0.237 |
0.337 |
0.531 |
0.674 |
|
6" |
6.625 |
0.134 |
0.280 |
0.432 |
0.718 |
0.864 |
Inconel 718 Welded Pipe & Tube Size Range
|
NB Size |
OD (mm) |
Wall Thickness Range |
Standard |
|---|---|---|---|
|
1" |
33.4 |
Sch 10S – XXS |
ASTM B725 / ASME SB725 |
|
1½" |
48.3 |
Sch 10S – XXS |
ASTM B725 / ASME SB725 |
|
2" |
60.3 |
Sch 10S – XXS |
ASTM B725 / ASME SB725 |
|
3" |
88.9 |
Sch 10S – XS |
ASTM B725 / ASTM B730 |
|
4" |
114.3 |
Sch 10S – XS |
ASTM B725 / ASTM B730 |
|
6" |
168.3 |
Sch 10S – Std |
ASTM B725 / ASTM B730 |
|
8" |
219.1 |
Sch 10S – Std |
ASTM B725 / ASTM B730 |
|
10" |
273.0 |
Sch 10S – Std |
ASTM B725 |
|
12" |
323.9 |
Sch 10S – Std |
ASTM B725 |
|
16" |
406.4 |
Sch 10S – Std |
ASTM B725 |
Inconel 718 Pipe Weight Chart
|
NB Size |
OD (mm) |
SCH 40 (kg/m) |
SCH 80 (kg/m) |
SCH 160 (kg/m) |
|---|---|---|---|---|
|
1/2" |
21.3 |
1.27 |
1.62 |
2.55 |
|
3/4" |
26.7 |
1.69 |
2.20 |
3.24 |
|
1" |
33.4 |
2.50 |
3.24 |
4.55 |
|
1½" |
48.3 |
4.05 |
5.41 |
7.66 |
|
2" |
60.3 |
5.44 |
7.48 |
11.11 |
Weights are theoretical for Inconel 718 (density 8.19 g/cm³). Actual weights may vary ±10%.
Types of Inconel 718 Pipes & Tubes
Inconel 718 Seamless Pipe
ASTM B829 / ASME SB829
Inconel 718 Welded Pipe
ASTM B775 / ASME SB775
Inconel 718 Seamless Tube
ASTM B829 / ASME SB829
Inconel 718 Welded Tube
ASTM B751 / ASME SB751
Inconel 718 EFW Pipe
Electric Fusion Welded
Inconel 718 ERW Pipe
Electric Resistance Welded
Inconel 718 Coiled Tubing
Continuous lengths – subsea / downhole
Inconel 718 Capillary Tube
OD ≤ 6 mm, instrumentation
Other Inconel 718 Pipe & Tube Products
- Inconel 718 Round Pipe
- Inconel 718 Square Tube
- Inconel 718 Rectangular Tube
- Inconel 718 Hydraulic Tube
- Inconel 718 Heat-Exchanger Tube
- Inconel 718 Boiler Tube (ASME SB829)
- Inconel 718 Condenser Tube
- Inconel 718 Instrumentation Tube
- Inconel 718 U-Bend Tube
- Inconel 718 Thin-Wall Tube
- Inconel 718 Large-Diameter Pipe
- Inconel 718 Custom-Length Pipe / Cut Pieces
Service Environment Guidance
| Environment / Medium | Max Temp Recommendation | Notes |
|---|---|---|
| Oxidising atmospheres (air, steam) | 980°C (annealed) | Cr₂O₃ scale forms; usable to 980°C if stress is low |
| Sour gas (NACE MR0175 / ISO 15156) | 232°C (aged condition, ≤ 40 HRC) | Must meet HRC ≤ 40 requirement; solution-annealed condition preferred for higher H₂S |
| High-purity / deionised water (nuclear) | 350°C | SCC resistance superior to Alloy 600; validated in PWR primary-water chemistry |
| Sea water / marine splash zone | Ambient–80°C | Excellent pitting & crevice resistance; PREN ≈ 22 (Mo + Nb contribution) |
| Reducing acids (HCl, H₂SO₄) | Not recommended | Low Mo content limits resistance; consider Alloy 625 or C-276 instead |
| Aerospace combustion gases | 700°C (aged, load-bearing) | Primary alloy for turbine discs & fasteners up to 700°C |
Heat Treatment of Inconel 718 Pipes & Tubes
The properties of Inconel 718 pipe are highly dependent on heat treatment condition. There are two standard conditions:
- Solution Anneal: 954–982°C (1750–1800°F), hold 1 h per 25 mm section, rapid air cool or water quench.
- Precipitation (Age) Hardening: Two-step aging — 718°C (1325°F) / 8 h, furnace cool to 621°C (1150°F) / 8 h, air cool. Total aging time ≈ 18 h. Develops γ″ (Ni₃Nb) and γ′ (Ni₃(Al,Ti)) strengthening phases.
- Stress Relief (if needed): 870°C (1600°F), 4–10 h, air cool. Used after heavy cold work before final aging.
- Annealing Atmosphere: Vacuum, argon, or dry hydrogen preferred. Avoid sulphur-bearing atmospheres.
Welding Inconel 718 Pipes & Tubes
Inconel 718 is one of the most weldable precipitation-hardened superalloys due to its sluggish γ″ precipitation kinetics. Welding guidelines:
- Recommended Processes: GTAW (TIG) and GMAW (MIG) with matching filler ERNiFeCr-2 (FM 718) or over-alloyed ERNiCrMo-3 (FM 625).
- Preheat: None required. Maintain interpass temperature ≤ 150°C to avoid hot cracking.
- Post-Weld Heat Treatment (PWHT): Full solution anneal + double age for maximum strength. Direct age (without re-solution) acceptable when residual stress is low.
- Shielding Gas: 99.99% Ar or Ar + 1–2% H₂ for GTAW; Ar + 25% He optional for deeper penetration.
- Special Note — Strain-Age Cracking: Alloy 718 was specifically developed for resistance to strain-age cracking, making it far more weldable than other precipitation-hardened superalloys (e.g., Waspaloy, Alloy 263).
Key Advantages of Inconel 718 Pipes & Tubes
- Exceptional high-temperature strength — retains > 1000 MPa tensile up to 650°C, surpassing most stainless steels and many other nickel alloys.
- Outstanding weldability — uniquely resistant to post-weld strain-age cracking thanks to slow γ″ precipitation kinetics.
- Cryogenic toughness — remains ductile to −253°C, suitable for LNG and aerospace cryogenic applications.
- Good corrosion resistance — withstands oxidation, pitting, and stress-corrosion cracking in diverse environments.
- Age-hardenable in tubular form — pipes and tubes can be solution-treated, welded, then aged to full strength on-site.
- Wide specification coverage — qualified under ASTM, ASME, AMS, API 6ACRA, and NACE MR0175.
Applications of Inconel 718 Pipes & Tubes
The unique combination of high strength, toughness, and corrosion resistance makes Inconel 718 pipe and alloy 718 tube indispensable across the most demanding industries in the world:
- Aerospace & Gas-Turbine Engines: Compressor bleed-air ducting, turbine exhaust manifolds, and fuel-system tubing operating up to 700°C.
- Oil & Gas — Subsea & Downhole: HPHT well completion tubing, control-line capillary tubes, and choke & kill manifold piping per API 6ACRA / NACE MR0175.
- Nuclear Power: PWR reactor-internals hydraulic tubing, steam-generator instrumentation lines, and spent-fuel-pool heat-exchanger tubes.
- Cryogenic Systems: LNG vaporiser tubes, liquid-hydrogen transfer lines, and rocket-engine propellant ducting down to −253°C.
- Chemical & Petrochemical: Reactor effluent tubing, acid-regeneration piping, and high-pressure autoclave lines in oxidising conditions.
- Power Generation (Land-based Turbines): Combustion-can crossfire tubes, fuel nozzle assemblies, and exhaust-frame ducting.
- Automotive & Motorsport: Turbocharger exhaust tubing, wastegate lines, and EGR cooler tubes exposed to > 900°C gas temperature.
- Marine & Offshore: Seawater-cooled condenser tubing, fire-water deluge piping, and riser tensioner hydraulic lines.
- Defence & Space: Missile motor cases, launch-vehicle pressurant tubing, and satellite thruster feed lines.
- Medical & Pharmaceutical: Orthopaedic implant cannulae, dental-instrument tubing, and sterile-process transfer lines.
- Tooling & Industrial: Extrusion press container liners, glass-forming mandrel tubes, and high-temperature thermocouple sheaths.
- Fastener & Spring Stock: Coiled tubing blanks subsequently swaged into bolts, studs, and springs for turbine casings.
For applications requiring maximum corrosion resistance rather than strength (marine, chemical acid service), compare with Inconel 625 Pipes & Tubes. For high-temperature furnace service above 700°C, consider Inconel 601 Pipes & Tubes or Incoloy 800H Pipes & Tubes.
Related Products
Inconel 718 Tube Price
| Inconel 718 Tube Price per Kg | Price in USD |
|---|---|
| 718 Alloy Tube Price in India | $46 per kg |
| Alloy 718 Tube Price in Japan | $51 per kg |
| UNS N07718 Tube Price in UK / Europe | $54 per kg |
| Alloy WERKSTOFF NR. 2.4668 Tube Price in USA | $65 per kg |
Frequently Asked Questions — Inconel 718 Pipes & Tubes
What is the difference between Inconel 718 and Inconel 625 pipes?
Inconel 718 is a precipitation-hardenable alloy (strengthened by γ″ Ni₃Nb and γ′ Ni₃(Al,Ti)) that achieves tensile strengths above 1300 MPa after aging. Inconel 625, by contrast, is a solid-solution-strengthened alloy with much higher molybdenum content (8–10% vs 3% in 718), giving it superior corrosion resistance in reducing acids and chloride environments but lower mechanical strength (~830 MPa annealed). Choose 718 when high-temperature strength and fatigue resistance are the priority; choose 625 when corrosion resistance is paramount. Learn more about Inconel 625 Pipes & Tubes →
Which ASTM / ASME standards cover Inconel 718 seamless tubes?
Seamless Inconel 718 tubes are primarily covered by ASTM B829 / ASME SB-829 (seamless nickel-alloy pipe & tube, general service). For welded forms, refer to ASTM B775 / ASME SB-775 (welded pipe) and ASTM B751 / ASME SB-751 (welded tube). Aerospace grades additionally reference AMS 5589 (seamless tube) and AMS 5590 (seamless pipe). All specifications require UNS N07718 chemistry.
What is the maximum service temperature for Inconel 718 tubing?
In the aged (precipitation-hardened) condition under sustained load, the practical limit is approximately 700°C (1300°F); above this temperature the γ″ phase over-ages and strength drops rapidly. In the annealed condition with low or no stress, 718 can see short-term excursions up to 980°C (1800°F) — useful for oxidation-resistant ducting. For continuous high-temperature, high-stress duty above 700°C, consider Waspaloy or Haynes 282.
Does Inconel 718 pipe require post-weld heat treatment (PWHT)?
Yes, to restore full mechanical properties a solution anneal (954–982°C) followed by a double-age cycle (718°C / 8 h → furnace cool → 621°C / 8 h) is recommended. However, Alloy 718 was specifically developed to resist strain-age cracking, so a direct age (skipping the re-solution step) is sometimes acceptable when residual welding stresses are low — consult your project specification for the approved PWHT cycle.