------>>>>>> Download a printable pdf file showing each rivet in its true-to-life size.
Common applications:
Purse straps - 8mm normally recommended for fabric straps, 10mm for vinyl /leather straps.
Key fobs (aka "snap" tabs) - 6mm, 8mm, crystal
The above are just suggestions. There is flexibility in sizes for each application. Generally speaking, use longer rivets for thicker material and shorter rivets for thinner.