Are you looking for the **Indexing Head**? So today we will study the **Definition, Methods in Detail(All) and Its Formula, Indexing in Milling Machine.** Here you will get the articles of Mechanical Engineering in brief with some key points and you will get to know an enormous amount of knowledge from It. So If you find this articles helpful, please let us know in the comment box, either if any correction required too, also let us know in the comment box.

## Indexing Head Definition:

The indexing head is the operation of dividing the periphery of a workpiece into any number of equal parts.

While cutting the spur gear, equal spacing of the teeth on the gear blank is performed by indexing.

The indexing head can also be used for producing a square or hexagonal bolts, cutting splines on shafts, fluting drills, taps, reamers, etc.

The indexing can be achieved by using a special attachment known as dividing head or index head.

## There is a total of 5 Indexing Head Methods:

**Direct Indexing****Simple Indexing****Angular indexing****Compound Indexing and****Differential indexing**

### 1. Direct Indexing Head:

The direct indexing is also called Rapid indexing, and it is used when a large number of pieces are indexed with a small division.

This operation can be done in both plain and universal dividing head. When using the Universal head, the worm and worm wheel are first disengaged.

The required number of division on the work is obtained by means of the rapid index plate which is fitted at the front end of the spindle nose. The plate has 24 equally spaced holes.

The spring-loaded pin can be pushed into any of the holes to lock the spindle with the frame.

For indexing, the pin is taken out first and then spindle is rotated by hand, and after the required position is reached it is again locked by the pin.

When the plate is turned through the required part of the revolution, the dividing head spindle and the work are also turned through the same part of the revolution.

With Rapid indexing plate of 20 holes, it is possible to divide the work into an equal division of 2,3,4,6,8,12 and 24 parts which are all the factors of 24.

To Find the index movement, find the total number of holes in the direct index plate by the number of divisions required in the work, If N is the number of divisions required on the work then,

[Number of holes be removed= 24/N]

**Preparing for Competitive Exam? If Yes, then must go for this book:**

** The most valuable and trusted Mechanical Objective book by R S Khurmi 5000+ Objective.**

### 2. Simple Indexing Head:

Simple indexing is also called as 9 indexing. It is more accurate and has a large range of indexing than rapid indexing.

For indexing, the dividing head spindle is turned by the by index crank. The figure is shown:

The worm shaft carrying the crank has a single-threaded worm which meshes with worm gear having 40 teeth, 40 turns of the crank are necessary to rotate the index head spindle through one revolution.

Therefore, one complete turn of the index crank will cause the worm wheel to make 1/40 of a revolution. To facilitate indexing to the fraction of a turn, Index plate is used to cover practically all number.

The Index plate with a circle of holes manufactured by the brown and sharp company are:

- Plate No 1- 15,16,17,18,19,20
- 2- 21,23,27,29,31,33
- 3- 37,39,41,43,47,49

To find the index crank movement, divided 40 by number of division required on the work,

[Index crank movement= 40/N]

Where N is the number of division required on the work.

**Looking for some other topics explanation? I have discussed in details:**

### 3. Angular Indexing Head:

The angular indexing is the Process of dividing the periphery of work in angular measurements.

There are 360 degrees in a circle, and then the index crank is rotated by 40 number of revolution,

and the spindle rotates through 1 complete Revolution or by 360 degrees, one complete turn off the crank will cause the spindle and the work to rotate through 360/40=9 degrees.

Therefore in order to turn work through a required angle, the number of turns required for index crank can be calculated by the number ‘9’.

Angular displacement is expressed in minutes then the terms of the index crank can be calculated by dividing the angle by 540.

If it is expressed in seconds then it is divided by 32400.

When a result is a whole number, the index crank is rotated through the full calculated number.

If the result is a fraction and a whole number,

the part of the revolution of the crank after turning the whole number is calculated by multiplying is suitable for numbers to the numerator and denominator of the fraction, defecation to make the denominator of the fraction is equal to the number of holes in the index plate circle and the now numerator number for holes to be moved by the index Crank.

The index crank Movement= Angular displacement of work, in degrees **/** 9

= in minutes **/** 540

= in seconds **/** 32400

**Preparing for Competitive Exam? If Yes, then must go for this book:**

** The most valuable and trusted Mechanical Objective book by R S Khurmi 5000+ Objective.**

### 4. Compound Indexing Head:

In Compound indexing, there are two separate movements of the index crank in two different hole circles of one index plate to get the crank movement.

The index plate is held stationary by Lock pin heed which engages with one of the whole circle of the index place from the back.

For indexing first, the crankpin is rotated by the required number of the spaces in one of the holes of the circle of the index plate and then the pin is engaged with the plate.

The second index movement is done by removing the real lock pin and the rotating the plate together with the index crank forward or backward through the calculated number of spaces of another hole circle, and the lock pin is engaged.

The net movements are the sum of the movement, therefore,

[40/N = n_{1 }/N_{1} + n_{2}/N_{2}]

Where N is the number of divisions required

N_{1} is the hole circle used by the crankpin

N_{2} is hole circle used by the lock pin

n_{1} is space moved by the crankpin in N_{1} hole circle

n_{2} is the spaces moved by the plate and the crankpin in N_{2} hole circle.

The basic knowledge about indexing, I think now you know.

#### So let’s look forward to solving the problem,

Q 1. **Find out the index movement required to mill a hexagonal Bolt by direct indexing. The rapid index plate has 24 holes.**

Solution: Number of holes to be moved = 24/N

=24/6=4

Therefore after machining one side of the bolt, the index plate has to move by 4 holes for next face to the machine.

Q 2. **Set the dividing head to mill 30 teeth on spur wheel blank by simple indexing**.

Solution: Index Crank movement = 40/N

= 40/30

= 4/3

= 4/3 * 7/7 =1+(7/21)

1 Full turn and 7 holes in 21 holes circle of the index plate.

## Indexing Head PDF:

Download PDF from Facebook or Telegram group.

Join the **Facebook** group**: Engramritkumar Facebook**

Connect **Telegram** group**: Engramritkumar Telegram**

Join **WhatsApp** group: **Engramritkumar WhatsApp**

Today we have learned about **Definition, Methods in Details(All) and Its Formula, and Indexing head in Milling Machine**. If I have missed something, kindly inform me through commenting. If you **like** this article, don’t forget to **share it** on **social networks. Subscribe our website** for more informative articles. Thanks for reading it. **Thank you.**

**Other Top Trending Post in details:**

Help others to read by share this Post

## Comments 4

I have Q differential indexing

Author

Yeah! Go Ahead !!!!

I have Q differential indexing

Author

Yeah! Go Ahead !!!!