ABOUT TYPES OF LAP JOINTS

 WHAT ARE TYPES OF LAP JOINTS?

• In a lap joint, one overlaps the other and the two plates are riveted together.

       * Classification of lap Joints Based on Number of Rows of Rivets :

• Depending upon the number of rows of the rivets, the lap joints are classified as :

1. Single riveted lap joint :

• In a single riveted lap joint, there is only one row of rivets.

      2. Double riveted lap joint :

• In a double riveted lap joint, there are two rows of rivets.

     3. Triple-riveted  lap joint :

• In a triple-riveted lap joint, there are three rows of rivets.

     4. Quadruple riveted lap joint :

• In a quadruple riveted lap joint, there are four rows of rivets.

    * Classification of Lap Joints Based on Layout of Rivets : 

• Depending upon the number of the rivets in each main plate, the butt joints are classified as :

1. Single riveted butt joint :

• In a single riveted butt joint, there is only one row of rivets in each main plate.

      2. Double riveted butt joint :

• In a double riveted butt joint, there are two rows of rivets in each main plate.

      3. Triple-riveted butt joint :

• In a triple-riveted butt joint, there are three rows of rivets in each main plate.

      4. Quadruple riveted butt joint :

• In a quadruple riveted butt joint, there are four rows of rivets in each main plate.

      * Classification of Butt Joints Based on Layout of Rivets :

1. Chain riveted butt joint :

• When the rivets in the various rows are opposite to each other, the butt joint is said to be the chain riveted butt joint.

      2. Zig-zag riveted joint :

• If the rivets in the adjacent rows are staggered in such a way that every rivet is in the middle of the two rivets of the opposite row, the butt joint is said to be a zig-zag riveted butt joint.

      * Classification of Butt Joints Based on Relative Lengths of cover Plates :

• Depending upon the relative lengths of cover plates, the double strap butt joints are classified as :

1. Equal strap butt joint :

• When the lengths of the two cover plates (i.e. straps) are equal, the butt joint is said to be equal strap butt joint.

     2. Unequal strap butt joint :

• If the lengths of the two cover plates (i.e. straps) are unequal, the butt joint is said to be unequal strap butt joint.