Spot welding and how it is done

1. Bijon Saha
DME – 51
2nd Year
PPT On :- Spot Welding

2. WHAT IS WELDING?
 Welding is a permanent
metal joining process by
which two similar or
dissimilar metals may be
joined by heating them to
a suitable temperature
with or without filler
metals and with or
without external pressure.

3. Different TYPES OF WELDING

4. SPOT WELDING
 Resistive Spot Welding
is a process in which
contacting metal
surfaces are joined by
the heat obtained from
resistance to electric
current.

5. Different TYPES OF SPOT WELDING
MACHINES

6. PARTS OF THE MACHINE

7. WORKING PRINCIPLE
H = I2RT
I – Current
R – Resistance of the
conductor
T – Time of current flow

8. HOW IT WORKS?

9. ADVANTAGES:
 Quick and Easy
 No need of Flux and Filler metals
 Multiple sheets joined together at the same
time
 No dangerous open flames
 Saves production cost
 Dimensional Accuracy

10. LIMITATIONS:-
 Difficulty for maintenance or repair
 Generally have higher cost than
most arc welding equipment
 Low tensile and fatigue strength
 The full strength of the sheet cannot prevail
across a spot welded joint

11. APPLICATIONS
 Automobile industry
 Dental Prosthesis
 Batteries
 Nuts and Bolts