Tacking Rivets:

When the maximum distance provided at (b) and (c) is exceeded, tacking rivets (not subjected to calculated stress) are used. They have a pitch line not exceeding 32 t or 300 mm whichever is less. The lines of rivets shall not be apart at a distance greater than these pitches. In composite tension members, tacking rivets are provided at a pitch in line not exceeding 1000 mm. In compression members, this maximum pitch is 600 mm.

Grip of Rivets:

When the grip of rivets exceeds 6d the number of rivets required by design calculation shall be increased by 1% for each additional 1.5 mm grip. However, the grip should not exceed 8d in any case.