3 Tips for Repairing a Broken Staple Gun

By understanding how a staple gun works, the user can eliminate many frustrating situations. Staple guns use a spring loaded firing mechanism where a hammer is driven down forcefully enough to splice off a staple, penetrate the materials being joined, and bend the edges of the staple back toward the staple gun. As the hammer rises, the next staple is forwarded by a spring which pushes the staple bar forward along guide rails, allowing the staples to feed evenly. Since the mechanism works together in a system, if there is one problem, the entire process falls apart. Three common areas of issue are a jam within the staples themselves, a worn out spring, or a clogged hammer.

Staple Jam

Make sure the staples being used are the correct size for the staple gun. Guide rails along which the staples feed are designed for a specific distance between each staple point. Even a fraction of a millimeter can cause an uneven flow of staples and result in a staple jam. 

If nothing is coming out of the stapler at all, a staple jam is most likely the issue. Open the staple gun and remove the bar of staples.  Slide the spring back and forth to check that the staples are able to freely be forced out. If the spring will not move, there might be a staple lodged in the guide rails or around the spring preventing motion. Hold the stapler up to a light source, viewing the gap where the staple should be feeding. If light cannot be seen, there is at least one staple jammed in between whether it is visible or not. A flat head screwdriver or butter knife can often remove staples which can be seen. If the staple cannot be seen, attempt to slide the screwdriver through the feed to dislodge it. If this does not work, snap the head back down on the staple gun (without replacing the staples) and slam the head of the stapler 10 times against the heel of your shoe or other rubber surface. Often the combination is enough to dislodge the staple.

Worn Out Spring

If the spring cannot maintain adequate tension, there will not be enough force to continuously feed new staples. Open the stapler, slide the spring back, and let go. The spring should rapidly contact the bar of staples. If the spring's reaction is slow or not forceful enough, a new spring is needed.

Clogged Hammer

Misshapen staples can be the product of the hammer not hitting the individual staple in the correct stop, causing disfigurement. Make sure the staples are the correct size. If the staples are sized correctly, open the staple gun and check the hammer by pressing down on the head of the stapler. The hammer should freely slide downward without obstruction. Obstructions can often be dislodged with a flat head screwdriver. If dirt, grease, or gun has clogged or is impeding the hammer, WD40 or white vinegar can be utilized as a degreaser to remove debris. Adding a small amount of lubricant to the hammer can also ease tensions and help the stapler function.