The problem of stamping special size holes should be noted
(1) For the punching of the range of the minimum aperture punching φ0.8——φ1.6, use a special punch.
(2) When punching thick plates, use a larger one than the machining hole. Note: At this time, if the mold of the normal size is used, the punch thread will be damaged.
(3) The cutting edge portion, the ratio of the minimum width to the length should generally not be less than 1:10.
(4) The relationship between the minimum size of the punch edge portion and the thickness of the plate. It is recommended that the minimum size of the punch edge portion be twice the thickness of the plate.