Abstract: Based on the study of forming principle of formation of feed direction. Burrs in metalcutting, a physical parameter of determining the generating of I type feed direction burr ——critical tool cutting edge angle βrI is given. And the main factors which influence critical tool cutting edge angle are studied, and related theory analysis are made. Furthermore, some new controlling methods and technologys to restrain or decrease the feed direction burrs in machining processes are developed.

Key words: Burr, Control, Critical tool cutting edgeangle, Metal cutting