Shaft (mechanical engineering)

A shaft is a rotating machine element, usually circular in cross section, which is used to transmit power from one part to another, or from a machine which produces power to a machine which absorbs power.
Types.
They are mainly classified into two types.
Materials.
The material used for ordinary shafts is mild steel. When high strength is required, an alloy steel such as nickel, nickel-chromium or chromium-vanadium steel is used. Shafts are generally formed by hot rolling and finished to size by cold drawing or turning and grinding.
Standard sizes.
Source:
Transmission shafts.
The standard lengths of the shafts are 5 m, 6 m and 7 m.
Stresses.
The following stresses are induced in the shafts.
Design stresses.
The maximum permissible (design) stresses in bending (tension or compression) may be taken as:
The maximum permissible (design) shear stresses may be taken as: