Inconel and Incoloy are two different families of nickel-based alloys, both originally developed by Special Metals Incorporated, which owns the Inconel and Incoloy trademarks. The key difference is nickel content: Inconel grades carry more nickel for better high-temperature performance, while Incoloy grades are more economical.
What is Incoloy?
Incoloy grades are nickel-based alloys primarily alloyed with chromium. More than ten grades sit within the family; the two most widely used are Incoloy 825 and Incoloy 925.
What is Inconel?
Inconel grades are also nickel-based alloys primarily alloyed with chromium, but their nickel content is generally much higher than Incoloy grades. This improves performance at higher temperatures, where they retain more of their strength, though it makes them more expensive. There are up to twenty grades in the Inconel family, with Inconel 718 and Inconel 625 the most widely known and used.
Inconel 625 is lower strength but has excellent corrosion resistance across a wide range of aggressive environments, so it is commonly used in chemical processing components. Inconel 725 is similar to Inconel 625 in composition, and therefore corrosion resistance, but subtle alloying additions and an additional heat treatment roughly double its strength.
Inconel 718 is a much higher-strength grade that retains most of that strength at high temperature, making it widely used in aerospace applications such as turbines, as well as a range of oil and gas uses.
We stock Alloy 625 and Alloy 718 as round bar from 5/8"-10" diameter (15.87-254mm), and Alloy 725 as round bar from 1"-4" diameter (25.4-101.6mm).