How to Troubleshoot a Staple Gun

A staple gun holds a clip of metal staples that can be used to fasten building materials as fast as the user can pull the trigger. Staples eject with force by a spring-loaded firing system that hammers one staple at a time with a single thrust into the materials being joined. Troubleshooting a staple gun such as the Arrow T50 is often as simple as unclogging a jam in the mechanism. This happens when a staple lodges inside the tool, usually at an angle so that no other staples can come out. Troubleshooting takes only a few minutes using household tools.

Upholsterer attaching textile to sofa using staple gun
credit: Zero Creatives/Cultura/GettyImages
How to Troubleshoot a Staple Gun

Verify the Staple Size

Check that the correct size staples are loaded in the gun. Staples are measured by the length of the sharp points, such as 7/16 inch. This information is printed on the side of the gun and listed in the instruction manual. If you aren't sure what size staple is in the stapler, look for the original staple package.

Check Inside the Staple Gun

Pull the two latches backward on the bottom side of the staple gun to release the sliding compartment that holds staples. Verify the gun is loaded with a strip of staples. Also check whether the staples are aligned properly, as any staple that's positioned at an awkward angle may not come out of its chamber while you attempt to staple.

Check the Rod and Spring

Examine the pusher rod, the piece surrounded by a metal spring, to make sure it can slide freely against the staples. The pusher rod places tension on the strand of staples, pushing them forward slightly each time the gun is used. Remove the staples, then slide the pusher rod back and forth. If it doesn't slide well, spray a short burst of lubricant on the rod and spring to make it slide easier. The spring should also offer adequate tension and bounce back into place when compressed and let go. If the spring seems too loose or stretched out, replace it.

Unjam a Staple Gun

In some cases, a stray staple jams inside the gun, rendering the entire tool inoperable until you unjam it. Remove all visible staples from the chamber, then hold the staple gun up toward a light source, looking for any blockages. Sometimes a staple veers off its guiding track, jamming along one of the gun's side walls. If this is the problem, pry the staple out with a bent paperclip. If you can reach part of the staple easily, needlenose pliers offer an even better removal option. The most common staple blockage happens at the front end of the staple gun.

Once the bent staple has been removed, place a strip of staples into the gun, close the chamber and squeeze the staple gun to release a staple. It should work properly.

Special Safety Precautions

Whether working with an electric, pneumatic or manual model such as any Stanley staple gun, wear eye protection while troubleshooting the device. Keep your hands and other body parts away from the stapling area to avoid injury. Unplug or disconnect an electric or pneumatic staple gun when unjamming the device.


James Clark

James Clark began his career in 1985. He has written about electronics, appliance repair and outdoor topics for a variety of publications and websites. He has more than four years of experience in appliance and electrical repairs. Clark holds a bachelor's degree in political science.