- OVERLAP :- IT IS CAUSED BY OVERFLOW OF WELD METAL WITHOUT FUSION OVER THE PARENT METAL.
- UNDERCUT:- GROOVE/CHANEL ALONG THE TOE OF WELD CAUSED BY WASTAGE OF PARENT METAL DUE TO HIGH CURRENT OR LOW WELDING SPEED.
- SPATTER :- PARTICLES OF WELD SCATTERED AROUND WELD DUE TO HIGH CURRENT OR VOLTAGE.
- BLOW HOLES :- LARGE CAVITY DUE TO ENTRAPMENT OF GASES.
- POROSITY :- A GROUP OF SMALL GAS POCKETS
- INCLUSION :- ANY SLAG OR OTHER ENTRAPMENT MATTER IS AN INCLUSION DEPOSIT.
- INCOMPLETE ROOT PENETRATION :- FAILURE OF WELD TO FILL THE ROOT COMPLETELY DUE TO LOW CURRENT AND FAST SPEED OF WELD.
- LACK OF FUSION :- THIS OCCUR BETWEEN WELD AND PARENT MATERIAL, BETWEEN DIFFERENT LAYERS OF WELD METAL OR BETWEEN CONTACT SURFACE OF PARENT METAL. IT COULD BE CAUSED BY INCORRECT VOLTAGE, DIRT OR GREASE ETC.
