What is the difference between an upcut and a downcut router bit?

Question

Accepted Answer

An up-cut bit pulls chips upward and away from the cutting area. It provides excellent chip evacuation and is useful for deep cuts, pockets, mortises, and hardwood machining. However, it may lift surface fibers and cause minor tear-out on the top edge. A downcut bit pushes chips downward. It produces a cleaner top surface and is useful for veneered plywood, finished panels, lettering, and shallow profiles. Because chips are pushed into the cut, downcut tools are not always ideal for deep pocketing. The correct choice depends on which surface requires the cleanest finish and how efficiently chips must be removed.

Read Cutting wood with a CNC router