Is Incoloy 925 machinable?

Incoloy 925 is increasingly being used in Oil and Gas applications, as a lower cost alternative to Inconel 718. As such, it will be machined into a variety of downhole components such as measurement equipment and drill string parts, as well as valves, seal assemblies and hangers.

The mechanical properties of Incoloy 925 are quite similar to that of Inconel 718, their composition is primarily nickel, and both achieve their high strength through precipitation-strengthening, with the presence of fine hard precipitates throughout. Therefore, machining set-ups are also similar.

There are several challenging aspects to the machining of Incoloy 925. Firstly, it will work harden during the machining process which will increase the strength of the metal at the surface appreciably. It has relatively low thermal conductivity, so there is the potential for a build-up of heat at the tool tip during machining. This can lead to excessive tool wear, reducing tool life or requiring slower machining speeds. Finally, grades such as Incoloy 925 with their precipitation-strengthening, could suffer from abrasive wear to the tooling.

When combining these factors, correct tool selection and set-up are critical. Rigid tools with positive rake angles and machining patterns that limit work hardening of the material are recommended.

Langley Alloys currently stocks Alloy 925 as round bars from 4”-10” diameter (101.6-254mm), with hollow bars also available.

For More Information  

For more information about our range of alloys, please contact Langley Alloys today.