How long should a rivet be before driving or squeezing?

Several builders and customers of aircraft tools have asked how long a rivet should be before they drive or squeeze the rivet. The simple answer is the shank of the rivet should stick out 1-1/2 times the shank diameter before driving. There is a link to a mil-spec above that has the exact measurements in Table 3. If you follow the 1-1/2 times the shank diameter rule you will always be pretty close. Hope this helps those of you who may not have heard this before. Glenna