A-Z on shafts of inboard motor systems.

[NA me]

Hello again fellow boat builders,

i wish to learn about shafts, most inboard propeller shaft info is limited to installation.

1.what sorts of materials are there that are used to cast shafts
2.why are there multiple types of steel used? won't steel rust? (i know there will be martyr anodes, being its a marine enviroment won't the exposed parts of the shaft experience rusting?) i have some material engineering knowledge(austinistic steel etc2, was not a fan of that though )
3. how do i determine differences(limitations,performance, function) of shaft to be used for
-fast boats(racing)
-fishing boats
-tankers
-tug boats
4. what are the limitations for shaft type selection according to the material of the hull(wood, FRP, steel, alu)? or even size of vessel limitations?

to all boat builders do enlighten me. all your post will be very appreciated.

[gonzo]

There are basically bronze, monel and stainess steel (of different grades) as shafts. Shafts are not likely to be cast though, but extruded. Differences and limitations are determined by the characteristics of the materials. Gerr's book on propellers also explains about shafts. It is a great primer.

[NA me]

thx gonzo. appreciate it