In order to clarify the cutting mechanism of FRP, the quality of cut surface finish of unidirectional glass fiber reinforced plastics was investigated by changing the direction of glass yarn against the cutting direction. Cutting was operated under two-dimensional dry cutting conditions. The cut surface finish state of glass yarn end was discussed by taking the cut plastic surface state without any glassfiber as a standard surface. The following results were obtained by changing the both rake angle and depth of cut:
(1) The cut end states of glass yarn near the cut surface were classified into two modes with changing the direction of glass yarn, such as the hollow pit and the swollen proturberance (uncut glassfibers).
(2) The maximum hollow pit depth was almost twenty times of the maximum swollen proturberance height on changing the direction of glass yarn.
(3) The change in rake angle of cutting tool did not affect the surface finish state.
(4) The surface finish state became worse with increasing the depth of cut.