RAMAKRISHNA MISSION

SHILPAMANDIRA

Bijon SahaDME – 512nd Year

PPT On :- Spot Welding

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.

Different TYPES OF WELDING

SPOT WELDINGResistive Spot Welding

is a process in which contacting metal surfaces are joined by the heat obtained from resistance to electric current.

Different TYPES OF SPOT WELDING MACHINES

PARTS OF THE MACHINE

WORKING PRINCIPLE H = I2RT

I – CurrentR – Resistance of the conductorT – Time of current flow

HOW IT WORKS?

ADVANTAGES:Quick and EasyNo need of Flux and Filler metalsMultiple sheets joined together at the same

timeNo dangerous open flamesSaves production costDimensional Accuracy

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

APPLICATIONSAutomobile industry Dental ProsthesisBatteriesNuts and Bolts