Parts are joined together through welding using heat and pressure. Welding involves joining metal surfaces that are clean, smooth, and have matching microstructures. There are two main types of welded joints: butt joints, where two pieces are aligned in the same plane, and lap joints, where two pieces overlap. To make a butt joint, the welding area is cleaned, the pieces are tack welded together, welding is done from one side to the other, and the joint is allowed to cool before finishing.

1. PPRREESSEENNTTAATTIIOONN
OONN
WWEELLDDIINNGG

2. Welding

3. Welding
Parts are joined together by Fusion. Fusion is
brought about by a combination of heat and
pressure between parts being joined. In normal
welding processes very high temperatures and
little or no pressure is used.
Welding conditions
• Smooth joint surfaces that match each other
• Surfaces clean and free from oxides, grease and dirt.
• Metals to be joined have same microstructure

4. Butt Joint
A joint between two
members aligned
approximately in the
same plane

5. Lap Joint
A joint between two
overlapping members

6. Lap Joints
• Used to join two overlapping pieces of
metal.
• Single lap joint welded from one side.
• Single lap joint welded from two sides
develops full strength.
• Off set lap joint is used when two pieces of
metal need to be joined in the same plain.

7. PROCEDURE TO MAKE
BUTT JOINT
• Set the machine for welding purpose.
• Clean the welding area and put two pieces on the table.
• Make tack on the both end of the joints.
• Start welding from one side to another and of work pieces.
• Allow the joint to cool.
• Remove slag by chipping hammer.
• Finish the welding by wire brush

8. PROCEDURE TO MAKE
LAP JOINT
• Set the machine for welding purpose.
• Clean the welding area and put two pieces on the table.
• Make tack on both end of the joint.
• Start welding from one side to another side.
• Allow the joint to cool.
• Reweld if necessary.

9. SAFETY PRECAUTIONS
• Set the current and voltage properly.
• The welding should be done in properly
ventilated area
• Make sure that the floor is dry.