Spindles used in Drilling

Spindles are widely used in drilling. Drilling is one of the most common and easy machining process. About 75% of all metal or wood cutting material removed comes from drilling operations.

 

Drilling process
The process of drilling leads to the creation of holes that are right circular cylinders. This is done most by using a twist drill. A twist drill is a tool having a rotating drill bit which is used for drilling holes in various materials. With the help of a chuck, the drill bit is gripped at one end of the drill and is pressed or forced against the target material and then rotated. The tip of the drill bit perform the work of cutting into the target material like grinding off small particles as in oil drilling or slicing off thin shavings as in twist drills or auger bits.

 

Diagrammatic representation
In the figure given below, we depict a a cross section of a hole being cut using a common twist drill. The tools have flutes at the outside, specially made for the exit of the chips.

 

Types of drilling
Drilling is of various types depending on the mode of operation. The various types are as follows:

Characteristics of drilling
There are certain characteristics of drilling that sets it apart from other powered metal cutting operations:

 

Work Area of drill press
We give below a diagrammatic view of the metal-cutting area of a drill press. By using a C clamp, the workpiece is held in place. The cutting forces can be at times very large. So it is advisable not to hold a workpiece by hand during drilling. Wood is often used underneath the part to be cut so that the drill bit can overshoot without destroying the table. The cutting table also has holes for drill overshoot as well as weight reduction. As seen in the figure, the spindle is just at the top to hold the machine tool for drilling.