Metering rolls take care of an even distribution and a desired coating quantity on the application roller in roller coating machines. The metering roll never touches the workpiece directly; it will be set up exactly parallel to the application roll. With the adjustable gap between the application and the metering roll, the quantity of the to-be-applied coating material will be adjusted. In addition the viscosity as well as the federate have their influence in the coating quantity.

Metering rolls have their own adjustable drive with modern coating machines and can work in accordance to the unidirectional principle or to the reverse, and counterflow system respectively. At high-quality machines they have a chromium-plated surface which is always to be maintained clean to avoid residues to stay on the surface and dry on.

For the coarse wipe of metering and application rolls, doctor will be deployed.