1.industrial tool: Piercer(expander) of floor board
2.diameter :7.1~7.2mm
3.surface:sandblast
4.Four blade
5.long life

1.industrial  tool:Piercer(expander) of floor board
2.diameter :7.1~7.2mm
3.surface:sandblast
4.Four blade
5.long life and best quanlity

6.with two screws

: