What is N08825? Nickel Alloys

N08825 is the Unified Numbering System (UNS) designation for a nickel-based alloy most commonly known as Incoloy 825. The UNS system was created by a number of trade groups working together in the 1970’s, to reduce confusion from the same alloy being called different things or vice-versa. Each metal is indicated by a letter followed by five numbers, where the letter indicates the family of metals i.e. N for nickel-based alloys.

Incoloy® 825 (UNS N08825/W.Nr. 2.4858) is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. Incoloy 825 was primarily developed in order to better resist sulphuric acid. Copper additions are well-known to improve resistance to reducing environments, such as sulphuric acid. This property is also exploited in Ferralium 255 (containing 2% copper additions) and the much more highly alloyed Alloy 20 (3-4% copper) to great effect.

The mechanical properties of Incoloy 825 are relatively constant from very low temperatures (considered cryogenic i.e. -150degC) up to 540degC (100degF). Above this temperature, there is the possibility of undesirable microstructural phase changes that significantly reduce impact toughness and elongation. Incoloy is a registered trademark of Special Metals Corporation.

Langley Alloys carries a significant stock of Alloy 825 solid bar, from ¾” up to 10” in a large number of incremental sizes.  Popular applications currently served by our customers include valve components, thermowells and sensors, fasteners and also some downhole tooling which make use of its non-magnetic properties.


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For more information about nickel based alloys, please don’t hesitate to contact us today. We would be happy to answer any questions that you may have regarding specifications and common applications.