The Rivet Gallery Blog Rivet Length and What The Size Numbers Mean

As you probably know, there are many different types of pop rivets. There are the regular, open end, there's closed end/sealed, multigrip, bulbtite, monobolt, tri-fold, etc... The idea behind rivet sizing is that you don't need to know specific manufacturing requirements for each type of rivet to make your order.Rivets are sized by barrel diameter, and GRIP length. Rivets are not sized by ACTUAL barrel length. There are usually always two numbers associated with the rivet size (unless you get an off brand, economy box that just says large, or small... and you never know the capabilities of such rivets.)The first number corresponds to the rivet barrel diameter. (the part that goes through the hole). This number correlates to how many 1/32nds of an inch in diameter the barrel is. For instance, a 6 as the first number would translate to 6/32" or 3/16" diameter. (4/32" = 1/8" etc...)The second part of the number is the maximum GRIP the rivet can accomplish. This is the MAXIMUM thickness of material the rivet can bind together. This number represents how many 1/16ths of an inch in MAX GRIP the rivet can handle. For instance, if the second number is a 4 - then this = 4/16" or 1/4" MAX GRIP (likewise, a 16 as the second number would = 16/16" or 1" Max Grip...) Anything thicker than this max grip, and the rivet "blind side" will not function as designed. (In a monobolt, the mandrel head might not set in the barrel, or a trifold might not splay the legs - thus distributing the load).As you can imagine, two rivets with different manufacturing processes - both with 3/16" Max Grip, can and will have different ACTUAL barrel lengths. To keep this simple, all you need to know is how thick your material is, and match that to be just below the max grip, and you will be good to go. No need to know that a trifold is almost twice as long as a regular open ended rivet... As always, you should keep in mind that the specifications for the rivets suggest using the following drill bits for each diameter of rivet:1/8" Diameter - #30 Drill Bit5/52" Diameter - #20 Drill Bit3/16" Diameter - #11 Drill Bit1/4" Diameter - Ltr F Frill Bit Using a drill bit that is the actual barrel diameter may be too tight to allow the rivet to espand properly, or might hang up on one of the levels of material being riveted together.As always, if you have any questions, you can always send us a message.When you email us, we have the opportunity to research an answer for you before we contact you back - thus it is our preferred method of contact. ( Sales@TheRivetGallery.com )