Spot welding

Spot welding and how it is done

1. RAMAKRISHNA MISSION SHILPAMANDIRA 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 = I 2 RT 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