Drilling Machines: Types, Working, Parts, types and Price

Drilling machines are used to drill a cylindrical hole of the required diameter and depth into a metal workpiece. A drilling machine is one of the most important tools used in the workshop. The cutting tool which is also known as the drill is fitted into the spindle of the drilling machine.

A center punch is used to mark the indentation on the job where a drill operation has to perform. Then, the rotating drill is pressed at the location and is fed into the work.

Construction of a Drilling Machine

A drilling machine consists of Spindle, Column, Base, and drill head. The base is made of cast iron and the column is mounted vertically on the base. The table is designed to move up and down on the column. The drill spindle and electric motor are mounted on the column. The power is transmitted to the spindle from the motor through V elt or flat belt drive.

Types of Drilling Machines

Drilling machines comes in different types and sizes according to the type of operation,depth of cut, spindle speeds, amount of feed, method of spindle movement, etc. The different types of drilling machines are given below:

1. Portable drilling machine (Hand drilling machine)
2. Sensitive drilling machine (Bench drilling machine)
3. Gang drilling machine
4. Multiple spindle drilling machine
5. Deep hole drilling machine
6. Upright drilling machine
7. Radial drilling machine

Let us discuss all of these drilling machines one by one.

Portable Drilling Machine

A portable drilling machine is also called a Hand drilling machine. It is called portable because it can be carried from one place to another easily, is compact, and is very lightweight. It is used to drill holes on the workpiece at any required position, which is not possible with fixed drilling machines.

These drill machines are used extensively used in industries and are mostly used by production and maintenance operators and engineers. These drill machines operate at higher speeds and the motor used is generally of universal type.

Sensitive Drilling Machine

A sensitive drilling machine is also called a Bench drilling machine. It is used to drill a small hole at high speed on lighter jobs. The job is fed by the hand of the operator and the drilling feel can be felt by the operator, that is why the name Sensitive drilling machine is given to it. The drill machine is either mounted on the bench table or on the floor by means of fasteners. The sensitive drill machine can drill up to 15.5mm in diameter. A sensitive drilling machine consists of a table, spindle, drill head, base, column, and driving mechanism.

Gang Drilling Machine

As it is clear from the name, a gang drilling machine is having many drill operations on a single machine. The Gang drilling machine has a big table and a base. There are 4-6 drill heads are placed side
by side and all have different driving motors. A series of operations like drilling, reaming, counter boring and tapping are performed on the work job by simply shifting the job from one position to another on the work table.

Multiple Spindle Drilling Machine

A multiple Spindle Drilling Machine is used to drill a number of holes in a workpiece simultaneously. A multiple spindle drilling machine has several spindles. There is a single motor that is used to drive all the spindles. Thereby all the drills are fed into the work at the same time.

Deep Hole Drilling Machine

Deep Hole Drilling Machine is used to drill deeper holes in spindles and connecting rods etc. Less feed and high cutting speeds are required to drill deep holes. A non-rotating drill is fed very slowly into the rotating work and at high speeds. Coolant is being used while drilling in this machine.

Upright Drilling Machine

The upright drilling machine is used for medium-sized workpieces. It is heavier and bigger than a sensitive drilling machine. It can drill up to a hole of 50mm in diameter. For drilling different types of work, the machine is provided with a number of spindles speeds and feed.

Radial Drilling Machine

The radial drilling machine is used on medium to large and heavy workpieces. It is having a heavy round column mounted on a large base. The column supports a radial arm The arm, which is having a drill head on it, can be rotated in any position. The drill head can be made to slide on the radial arm. It consists of parts like a radial arm, drill head, base, column, and driving mechanism.

Drilling Machine Specifications

Before purchasing a drilling machine, one must consider the following factors:

1. The maximum diameter of the drill that it can handle
2. maximum travel of the spindle
3. numbers and range of spindle speeds and feeds available
4. Morse taper number of the drill spindle
5. floor space required
6. weight of the machine
7. The size of the largest workpiece that can be centered under the spindle
8. distance between the face of the column and the axis of the spindle
9. diameter of the table
10. Power input

Job Holding Devices

Safety is the top most priority in industries. So the jobs must be held properly before the drill operation starts. The drilling operation imparts a high torque on the job. If the job does not held properly, the ton the job might start get rotated which in turn could harm the operator. So the job should not be held by the hand while drilling operation. The various job-holding devices are:

1. Drill vise
2. ‘T’ – bolts and clamps
3. Step block
4. V – block
5. Angle plate
6. Drill jigs

Tools used in a drilling machine

Different tools are used for performing different operations and the tools used in drilling machine are

1. Drill
2. Reamer
3. Counter bore
4. Countersink
5. Tap

Drilling Machine Operations

The drilling machine do a different kind of following operations:

1. Drilling
2. Reaming
3. Boring
4. Counter boring
5. Countersinking
6. Spot facing
7. Tapping
8. Trepanning

Also, read about Lathe Machine