The roller conveyor furnaces for the hardening and tempering treatments are usually used for the production of components, having a smooth surface or that are loaded onto appropriate trays.
Quenching of components in water or oil may be performed through a conveying system specifically identified according to their shape/form or  with motor-driven lifts or mechanical traveling lifts.

The motor-driven roller lines consist of one or more furnaces, which come before or after the auxiliary systems, washers, loading and unloading systems.