Advanced Metalworking Solutions for
Naval Systems that Go in Harm's Way

Machining Alloy 625 Propulsor Components

New machining technologies and processes will improve cost and schedule for critical VCS propulsion system components. U.S. Navy photo


To mitigate the anticipated cost and schedule impact, the Navy Metalworking Center (NMC) is leading a ManTech project that will address the manufacturing challenges associated with machining these components.


In an effort to reduce the total ownership cost of Virginia Class Submarines (VCS), the Navy will change the propulsor material on Block IV hulls to Alloy 625, a nickel-based alloy that is highly corrosion resistant, but is very difficult to machine.

Technical Approach

The project team will investigate innovative machine tooling, alternative cooling technologies, and other improvements to the machining centers.


This project will improve the production rate and reduce the cost increase anticipated for production of Alloy 625 propulsors. Estimates to machine Alloy 625 are roughly three times the cost and duration of HY steel, but by avoiding 10 percent of this increased cost, this project is expected to save at least $6M over a five-year period.


A large-scale demonstration at BAE System’s Louisville facility in the fourth quarter of FY14 will determine progress toward product and process goals and will denote transition and implementation of the project results.




Brian Garza
PMS 450D


BAE Systems
Naval Surface Warfare Center, Carderock Division
PMS 450 Virginia Class Program Office
National Center for Defense Manufacturing and Machining