APU cast parts APU cast parts NMHG (Aerospace) (OP) 8 Jan 18 16:27 Does someone has any experience with APU Cast Parts? Can some one tell me something? Please and Thank You! RE: APU cast parts tbuelna (Aerospace) 9 Jan 18 01:26 APU's still use sand castings for some external housings/covers with shapes that would be impractical to produce by machining or other casting methods. Take a look at this picture of a disassembled APU. You can see several large sand cast housings/covers. RE: APU cast parts NMHG (Aerospace) (OP) 9 Jan 18 13:00 Thank You! The picture helped me a lot.