| 摘要 |
According to one aspect of the present invention, the present invention relates to a cutting tool (100) to form a preliminary opening in a stack (230) having two or more layers. The cutting tool has a shank (120). Moreover, the cutting tool (100) has a first portion (112) which has a first coating or at least one among the first coating (116) and a second coating (118), and the first coating (116) at least partially covers the first portion (112). The cutting tool (100) has a second portion (114) between the shank (120) and the first portion (112), and the second portion (114) has the second coating (118), and the second coating (118) at least partially covers the second portion (114). |
