Inconel 718
Fasteners
Mumbai · India
What Makes Inconel 718 Behave Differently
Inconel 718’s strength comes from precipitation hardening — during a controlled aging heat treatment, niobium in the alloy combines with nickel to form an extremely fine, evenly distributed phase called gamma double-prime (γ″, Ni₃Nb) throughout the metal’s structure. Those precipitates physically block dislocation movement far more effectively than the solid-solution strengthening used in grades like Inconel 625, which is why 718 can reach tensile strengths well beyond what 625 achieves — often exceeding 1200 MPa in the fully aged condition.
That strength is genuinely temperature-dependent on getting the heat treatment exactly right. 718 requires a specific solution anneal followed by a two-step aging cycle to form the correct precipitate size and distribution — too little time or the wrong temperature and the alloy under-ages, losing strength; too much and it over-ages, with the precipitates coarsening and the same loss of strength occurring from the other direction. This sensitivity is precisely why 718 fastener quality depends so heavily on a manufacturer’s heat treatment discipline, far more than most other nickel alloys.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our Inconel 718 fastener range is manufactured with controlled solution annealing and aging cycles, verified by hardness and mechanical testing under our ISO 9001:2015 quality system.
Where 718 Genuinely Earns Its Position
Exceptional Strength for a Nickel Alloy
Precipitation hardening delivers tensile strength that solid-solution grades cannot match, without sacrificing corrosion resistance.
Strength Retention Under Real Load at Heat
Holds meaningful structural strength up to roughly 700°C, well beyond where standard steel or stainless bolting has already softened.
Verified Heat Treatment Every Batch
Hardness and mechanical testing confirms correct precipitate formation rather than assuming the aging cycle went as planned.
Decades of Aerospace Service History
One of the most widely used and best-understood superalloys in gas turbine and airframe structural bolting worldwide.
Inconel 718 Detailed Properties
UNS N07718 Alloying Elements
- Nickel + Cobalt 50.0 – 55.0%
- Chromium 17.0 – 21.0%
- Niobium + Tantalum 4.75 – 5.50%
- Molybdenum 2.80 – 3.30%
- Iron Balance
Aged Condition (Typical)
- Tensile Strength 1240–1375 MPa
- Yield Strength 1030–1170 MPa
- Elongation 12–20%
- Hardness ~350–440 HB
- Testing MTC / NABL on request
Solution & Aging Cycle
- Solution Anneal ~955–1010°C
- First Age ~718–760°C
- Second Age ~620–650°C
- Precipitate Phase γ″ (Ni₃Nb)
- Verification Hardness + tensile testing
Inconel 718 vs X-750 vs Waspaloy
718 is often compared against two other age-hardenable superalloys solving related but distinct problems. The comparison below is the one we walk through with buyers before quoting, so the grade actually matches structural strength needs versus relaxation resistance versus higher-temperature capability.
| Property | Inconel 718 | Inconel X-750 | Waspaloy |
|---|---|---|---|
| UNS Designation | N07718 | N07750 | N07001 |
| Primary Precipitate | γ″ (Ni₃Nb) | γ′ (Ni₃(Al,Ti)) | γ′ (Ni₃(Al,Ti)) |
| Best Suited For | Maximum structural strength | Stress-relaxation resistance (springs) | Higher-temperature turbine components |
| Max Structural Temp | ~700°C | ~815°C | ~845°C |
| Relative Tensile Strength | Highest of the three | High | High |
| Relative Machinability | Moderate | Moderate | More difficult |
Our Inconel 718 Heat Treatment Process
Raw Material Verification
Bar stock chemical composition confirmed against UNS N07718 specification before machining begins.
Machining Before Hardening
Fasteners machined in the annealed, more workable condition prior to age hardening.
Solution Annealing
Controlled high-temperature anneal dissolves existing precipitates, resetting the microstructure for aging.
Two-Step Aging & Verification
Precise two-stage aging cycle forms the γ″ precipitate, followed by hardness and tensile testing to confirm correct strength.
Application Areas
Wherever structural strength has to hold up at genuinely high temperature.
Gas Turbine Engines
structural bolting
Airframe Structural Assembly
structure fastening
Rocket & Space Propulsion
engine component bolting
Power Generation Turbines
structural fastening
Oil & Gas Downhole Tools
demanding downhole environments
Nuclear Reactor Components
fastening applications
High-Performance Motorsport
fastening applications
General High-Temp Structural Use
maximum-strength applications
Standard Export Documentation
Prepared as standard practice for every Inconel 718 fastener shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and heat treatment record for every lot.
Hardness Test Report
Batch-level hardness verification confirming correct precipitation hardening response.
Certificate of Conformance
Confirms the shipment matches the purchase order specification and grade in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical and chemical testing available on request for critical applications.
Bill of Lading
Ocean or air freight shipping document confirming carrier, mode, and consignee details.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
Inconel 625 Properties & Applications
The solid-solution strengthened grade for corrosion resistance without post-weld heat treatment.
View Inconel 625 →Different Types of Inconel Fasteners
A detailed grade-by-grade comparison for choosing between all four Inconel grades.
View Inconel Grades →Uses & Specifications of Inconel Fasteners
A practical guide to applications and what to specify when ordering.
View Uses & Specifications →Titanium Grade 5 Fasteners
A lighter-weight, high strength-to-weight alternative for aerospace weight-critical applications.
View Titanium Grade 5 →Need Maximum Strength
at High Temperature?
Tell us the load and service temperature — we’ll confirm whether Inconel 718 or an alternative superalloy is the right fit for your structural application. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in