Exotic Propellers:

Casting pattern and machining of 24 inch diameter thruster for Navy NR-1 Pocket Nuclear Submarine.

These thrusters represent a recent design to production project which involved the complete solid model creation from an ancient blueprint (including complex 3T-T/3 blade/hub fillets), design synthesis of a match plate casting pattern with appropriate shrink factor and complex parting surfaces with draft, complete CNC machining of the pattern, and complete CNC machining of a 4 piece ship set from nickel aluminum bronze alloy including hand finishing of blade surfaces to better than a 32 microinch finish.

http://en.wikipedia.org/wiki/NR-1_Deep_Submergence_Craft