Abstract: The characteristics of CBN quill in surface grinding process are analyzed in theory. For a comprehensive understanding of the reason of CBN grain early fall off, which are maximum grain depth of cut increment and grain length of cot decrement, then the grain cutting force increment. This research experimentally investigat the relationship between grain cutting parameters and CBN quill grinding parameters, as a result, creep feed grinding and higher density of grain are beneficial to CBN quill grinding process.

Key words: CBN Quill, Fall off, Grinding depth, Grinding length