How Sheet Metal Screws Can Cause Electrical Fires

The picture above shows a sheet metal screw that was used to improperly fasten a dead front.  If you’re like most people you’re probably asking “what in the world is a dead front and how can it be improperly fastened?”  A dead front is the name electricians use to describe the cover on the front of your electrical service panel.  It is the part that the circuit breakers stick through, and it can be removed to service the interior of the panel.  For example, if you install a hot tub or replace a gas range with electric, an electrician will remove the dead front, add a properly sized breaker for your new appliance, and reinstall the dead front to protect from the high voltage inside.

The picture above shows a coarse threaded sheet metal screw, which can be very dangerous when used to attach a dead front cover.  Now you might be asking “Why wouldn’t you use a sheet metal screw on an electrical panel that’s made of sheet metal?”  Normally this type of screw would be perfect for this material, which is probably why this defect is so common, but in the case of an electrical service panel only machine screws should be used.  The problem is that the coarse threads of a sheet metal screw are sharp and they can cut through the protective covering on internal conductors.  This can result in a dangerous shock, arcing, and is a fire hazard.

This defect is usually the handy work of a “do it yourself” home repair job.  That is why I recommend having a licensed electrician do all maintenance and modifications to your electrical system.  They can start by replacing this dangerous screw with the proper dull, fine threaded machine screws.