What is the standard angle of the drill bit?
For example, HSS high-speed steel drill bit: vertex angle is generally 118 degrees, sometimes greater than 130 degrees; sharp blade; accuracy (blade height difference, symmetry, jitter) requirements are relatively low. There are many ways to correct the transverse blade. Hole roughing and less demanding, we generally use more. HM carbide drills: the top angle is generally 140 degrees; straight fluted drills are usually 130 degrees; and three edge drills are usually 150 degrees. The blade and nose (edge) are not sharp, often passivated, or inverted blade and chamfering, and require high accuracy. The horizontal edge is often into a S- shape, in favor of chip breaking
For example, the processing of aluminum parts is generally 118 degrees, because the processing of aluminum parts require fast feed, in the processing of small head angle of the cutting parts of the force will spread to the left and right sides, easy to cut. Casting angle of general 140-145, such as feed reasons for the high hardness of cutting force is slow, mainly concentrated in the front edge, if the bit is too sharp will wear out quickly, and the blade angle blade angle relative small blade due to natural force will be small and short.
The standard angle of the drill depends on the material of the drill and the material of the material to be machined. But the most common angle is 118 degrees.
