1. Detail and Assembly Drawing
Engineering drawing is the language of Engineers.
It is a powerful medium of communication between professionals.
For manufacturing any object detail as well as assembly drawing need to be drawn.
Its knowledge is therefore is of utmost importance.

2. Detail Drawing

6. Wooden Joints and its types
The joints which assemble two or more wooden members are called wooden joints.
Types of Wooden Joints
Corner halving Joint
Cross halving joint
Tee halving joint
Mortice and Tenon joint
Open mortice and tenon joint
Closed mortice and Tenon joint
Tee Bridle joint
Dovetail joint
Cogged design

7. Cross Halving Joint

8. Tee Halving Joint

9. Mortice and Tenon Joint

10. Open mortice and Tenon joint

11. Dovetail Joint

12. Screw Threads
A screw thread is formed by cutting a helical groove on a cylindrical surface.
This threaded cylindrical surface is called screw.
The screws are used to join two parts temporarily.
Screw threads are found on nuts, bolts , screws, set screws, studs etc.

13. Nomenclature of Screw Threads

24. Comparison
Left Hand Thread
Right Hand Thread

25. Couplings Shafts are generally available in 6 to 7 meter length.
For power transmission at longer distance longer shafts are required.
Length of shafts increased by joining two or more shafts.
Couplings are used to join two or more shafts .
Couplings transmits motion or power from one shaft to another.

26. Types of Couplings
Shafts couplings are broadly divided into two main groups:-
Rigid Coupling
Flexible coupling
Rigid Couplings connect the shaft in perfect axial alignment such as Flange Coupling, Muff Coupling etc.
Flexible Couplings connect the shafts which are not in perfect axial alignment such as Universal Coupling, Pin type flexible coupling etc.

27. Muff Coupling or box Coupling
It consists of a hollow cast iron cylinder called muff.
The internal diameter of the hollow cast iron cylinder is equal to the external diameter of two shafts to be connected.
There are key –ways in the two shafts at the ends and there is a key way in the hollow portion of the muff or box.
In the key-ways, a gib head key is inserted.
The key is taper taper for easy extraction of the key.
The taper in the key is 1:100.

28. Flange coupling ( Protected type)
In ordinary couplings, the bolt heads ad nuts are projected beyond the flanges which are projected beyond the flanges which are liable to cause injuries to material, men and machines around them.
To avoid this, protected type flange coupling is used.
It consists of two flanges made of cast iron and two shafts made of mild steel.

29. Half Lap Muff Coupling
In half lap muff Coupling, the ends of the shafts are made to overlap each other for a short length.
The taper in the overlaps at the ends prevents the shafts from separating, if pulled in opposite direction.
A hollow saddle key is used to connect the muff and the shafts.
Only one box is used to connect the two shafts together.
The taper in key is 1:100.
The key prevents the relative rotation between the two shafts and the muff.

30. Flanged Coupling (Non Protected type)

31. Flexible Coupling
In this Coupling, the motion or power is transmitted from one shaft to the other shaft with the help of driving pins rigidly bolted to one flange and loosely fitted to the corresponding holes in the other flange.
Flexible elements such as rubber washers or leather washers are used around the driving pins for preventing vibrations.
The flexible coupling are used to minimize starting shocks.