Upcut milling, downcut milling
Gegenlauffräsen, Gleichlauffräsen
Fresado de contramarcha y fresado a favor del avance
Fraisage en sens contraire, fraisage dans le sens de l'avance
Up-milling: If a router is guided manually, the advance feed has to be in counterrotation, i.e. the rotational direction of the router bit and the advance feed motion are in opposite directions.
Downcut milling means that rotational direction of the router and advance motion run parallel. This is only possible with controlled guidance of router and material, e.g. in stationary routers with automatic advance motion.