Why is my pneumatic nailer bending the nails?

Most often when the tool is bending the nails over, it is due to a lack of driving power due to worn o-rings or a lack of lubrication. The best way to correct low driving power is to clean the interior of the tool, install the appropriate o-ring kit and trigger valve assembly, using fresh o-ring lubricant. Other possible causes for nails bending are: 1) driver -- it is expected that the driver shows obvious wear at the tip. If it looks OK, it probably is. 2) driver piston assembly -- check to see if the driver threads have loosened in the piston. 3) fasteners -- defective, wrong collating angles, wrong fastener for the application. 4) air pressure too low