Originally Posted by goobscoob
well 3 hours of googling later I do finally understand that it was most likely because the material I was riveting was not thick enough. I had thought that the mandrels were being cut off by the rivet puller. Didn't know that there was already a pre-made breaking point inside the rivet. COOL
Pop rivets come in various lengths.
As an example a # 48 pop rivet is 1/8 inch in diameter and has a grip range
of 1/2 inch, BUT
, it's length is 5/8 of an inch.
Pop rivet guns, DO NOT cut the pop rivet mandril. The gun pulls the mandril until it actually shears.
Making sure the sheared mandril breaks off before the top of the rivet head requires a specific "grip range" pop rivet.
As another example you would not use a # 48 pop rivet to hold a small thickness, say 1/8 inch. for 1/8 inch the proper pop rivet size would be a # 44, or even a # 43.
The first number is the diameter of the rivet in 32"s of an inch, and the second # is it's grip range in 16's of and inch.
Using a pop rivet that has an excessive grip range, will always produce a sheared off mandril that sticks out above the rivet head.