Spot facing is a machining operation for producing a flat seat for bolt head, washer or nut at the opening of a drilled hole. The tool is called a spot facer or a spot facing tool. Spot facing is similar to counter-boring, except that it is shallower. Tools that are used for counter-boring can be used for spot facing as well.
44) Spot-facing is done to
Make surface flat so that bolt head can take proper seat on the surface
Related Cutting Tools MCQ - Machinist(Set-1) with Answers
Preventing digging of the ends of cutting edge
Material to be drilled
The point angle of a general purpose (standard) drill is 118°. This is the angle between the cutting edges (lips). The angle varies according to the hardness of the material to be drilled.
For general purpose use point angle of twist drill is 118 Degree.