Spur Gears

Spur gears are straight-toothed gear parts that transfer torque between parallel shafts through simple meshing, which suits moderate-speed, heavy-load power conveyance. They are mainly used in general-purpose reducers, material-handling machinery, agricultural transmission assemblies, machine tool drive trains, and light-duty industrial actuator units.

Because the teeth run parallel to the shaft axis, a spur pair develops no axial thrust, so bearings stay simple and the housing does not have to resist end load. That advantage fades as pitch-line speed climbs, where impact at the start of each mesh begins to govern noise and tooth wear. For the module and pressure angle behind that trade-off, see our guide to what is a spur gear, which also sets out where a helical gear is the better choice.