Need from mechanical expert !

[Apollo]

KNN... u tried rectangular shaft down ur karchng b4 rite?

[Watwheels]

There are rectangular cross-sectioned shafts. It depends on the application.

 

For cylindrical shafts it's faster and cheaper to machine than sq./rectangular ones cos due to the machines designed to fabricate them ie. turning machine. And the raw material such as steel rods are roll out in cylindrical shapes.

 

It's also easier to bore circular holes than machining a sq. hole for a shaft to fit.

 

A lot depends on apllication. It's not say dun have. For some shafts' end it's made sq. such that it can be tightened using a spanner.

[Watwheels]

Okay , for what i know is ; Solid vs Hollow Shaft,

 

Hollow ==> less Moment of Inertia = less twisting

 

Solid ==> more Moment of Inertia = more twisting

 

Like I said it all depends on application. Hollow shafts are mainly use to fabicate frames or some light weight application.

 

Solid steel/alloy shafts are for strength usually used for torque related applications.