what is the difference between 15 gauge and 18 gauge nails?
One advantage to 15-gauge nails is that they are collated at an angle, which allows the nose of the nailer to reach into tighter spaces. Brad nailers use smaller 18-gauge nails up to 2 inches long. ... They don't offer much shear or withdrawal strength though, so these nails are best used for wood-to-wood connections.