When drilling the ball face, if a standard twist drill is used, the point contact between the drill bit and the spherical surface makes the center line of the machining hole deviate from the center of the ball, and the precision requirement is often not obtained, and the guiding precision is not high. Now the standard twist drill bit can be improved to overcome the above shortcomings. The improved structure of the drill bit is shown in the figure, the top edge is removed, and the front and back knives are sharpened
Hollow Wall Anchor
Hebei Qianmu Fastener Manufacturing Co., Ltd , https://www.qmjgjfasteners.com