Editing Coupling (section)

=== Sleeve, box, or muff ===
A [[sleeve coupling]] consists of a [[pipe (fluid conveyance)|pipe]] whose [[Bore (engine)|bore]] is finished to the required tolerance based on the shaft size. Based on the usage of the coupling a [[Keyway (engineering)|keyway]] is made in the bore in order to transmit the [[torque]] by means of the key. Two threaded holes are provided in order to lock the coupling in position.

Sleeve couplings are also known as '''box couplings'''. In this case shaft ends are coupled together and abutted against each other which are enveloped by ''muff'' or ''sleeve''.

A ''gib head sunk keys'' hold the two shafts and sleeve together (this is the simplest type of the coupling) It is made from the cast iron and very simple to design and manufacture. It consists of a hollow pipe whose inner diameter is same as diameter of the shafts.
The hollow pipe is fitted over a two or more ends of the shafts with the help of the taper sunk key. A key and sleeve are useful to transmit power from one shaft to another shaft.