Summary
Both are precipitation-hardened alloys for large rotating parts. 706 was developed for very large land-based turbine forgings, and its scrap comes back as heavy forgings and turnings from that work.
706 carries roughly double the iron and no molybdenum, so it is worth less per tonne than 718 and must never be mixed into a 718 lot. See Inconel 718 scrap and Inconel 706 scrap.
Side by Side
| Inconel 718 | Inconel 706 | |
|---|---|---|
| Iron | About 18.5% | About 37.5% |
| Chromium | About 19% | About 16% |
| Niobium | About 5.1% | About 2.9% |
| Molybdenum | About 3% | None |
| Typical service | Aero engine discs, shafts, oilfield parts | Land gas turbine discs, wheels, spacers |
Composition Compared
Nominal compositions compared element by element. Values are the nominal figures from each grade page; change either grade to compare others.
On a handheld XRF: the clearest differences between Inconel 718 and Inconel 706 are iron (18.5% vs 37.5%), nickel (52.95% vs 41.65%) and molybdenum (3.05% vs 0%). Light elements such as aluminium, silicon, carbon and nitrogen need a light-element instrument, OES or a laboratory.
On the XRF
Switch the grade to see how the fingerprint changes. See how XRF sorts nickel alloys.
FAQ
What is the main difference between Inconel 718 and Inconel 706?
Inconel 718 has about 18.5% iron, 19% chromium, 5% niobium and 3% molybdenum. Inconel 706 has about 37.5% iron, 16% chromium, 2.9% niobium and no molybdenum.
Can Inconel 718 and Inconel 706 scrap be mixed?
No. Keep them separate. Mixing Inconel 718 and Inconel 706 in one lot usually means the buyer either re-sorts it or prices it as mixed, which costs the seller money.
What are the UNS numbers of Inconel 718 and Inconel 706?
Inconel 718 is UNS N07718 and Inconel 706 is UNS N09706.
Which has more nickel, Inconel 718 or Inconel 706?
Inconel 718, with about 53% nickel against about 41.6% in Inconel 706, using the nominal values on this site.
Sources and Review
Composition figures on this page are the nominal values from each grade's own page on this site, where the producer datasheet or standard is named in full. The comparison widget reads the same values. The sources behind the grades are listed below.
- Special Metals Corporation, INCONEL alloy 718 (SMC-045, 2007): Inconel 718 Buyer, Importer and Exporter
- Special Metals Corporation, Product Handbook of High-Performance Nickel Alloys: Inconel 706 Buyer, Importer and Exporter
Published by Mipra Steel, Khetwadi, Mumbai · Last updated