The problem of stamping special size holes should be paid attention to
(1) please use a special punch to punch the holes of the minimum aperture of either.
(2) for heavy plate punching, use a larger die than the machining hole.Note: at this point, if the normal size of the mold is used, it will cause damage to the punch threads.
(3) the ratio of minimum width to length shall not be less than 1:10.
(4) the relationship between the minimum size of cutting edge and plate thickness.It is recommended that the minimum size of the cutting edge of the punch should be twice the thickness of the plate