The most common type of gear is the spur gear. These gears have straight teeth and must be mounted on parallel shafts for their teeth to mesh with those of other gears. Spur gears can be manufactured by finish gear cutting or by precision gear grinding.

Spur gears can be used to increase or decrease the torque, or power, of a given object especially if the design will not allow for a side load on the support bearings. Spur gears are used to this effect in all types of industrial applications, pumps for fuel, lubricating oil and most fluids. Spur gears are also used in off shore winches and slewing rings on jib cranes on off shore oil rigs.