How Do Threaded Rivets Work?

Threaded rivets and rivet gun

The traditional rivet is essentially a red hot bolt without threads which gets inserted front side first into a hole. A sealing flange is made by pounding the back side of the inserted rivet with a sledge or an air hammer. On a threaded rivet, sometimes called a blind or pop rivet, that same sealing flange action can be done from the front side alone, without having to pound down the back side.

Drilling the Rivet Hole

Drill out a hole for each rivet that is going to be employed. Rivets are used to join two pieces of material, usually metal, so a hole that is slightly larger than the rivet diameter must be drilled first. High speed metal bits are the preferred drilling tool, and either a corded or battery operated drill will do the job.

Placing the Rivet

Push a threaded rivet with a protruding mandrel inside every hole that has been drilled. Make sure the front flange is seated against the metal piece that is to be joined. For light duty jobs like joining two pieces of plastic, there are threaded rivets that have an outside coating of rubber. These merely need to be screwed down with a regular screwdriver, and the pressure of the expanding rivet bulge on the back side can be infinitely monitored by each slight turn of the screwdriver.

Using the Rivet Gun

Slide the jaws of the rivet gun over the protruding mandrel, and contract the jaws tightly by gently squeezing the trigger control. Position yourself directly over the gun and the rivet, and unless this is a power rivet gun which will work with the press of an electrical button, you will need two hands to grip and pull the trigger to conclusion.

Securing the Rivet

Pull the trigger on the rivet gun as hard as possible. The mandrel has a bulb on the far end that when pulled, will come into contact with the back of the rivet,. This action will begin to fold the light metal of the rivet up in much the same way as an accordion folds up. The resulting fold in the soft metal will expand and flare out larger than the hole in which it has been placed. The flared back part will firmly be pressed up against the piece of joining metal, and will make a solid and strong holding bond.

Breaking the Mandrel

Pulling the trigger all the way back when the rivet is solidly in place, will cause the mandrel to break away from the actual rivet. On some rivet guns there is a pressure adjustment dial. Different sized rivets have different sized mandrels that also break away under more or less pressure. Depending upon how heavy or light-duty the rivet is, the mandrel break-away pressure can be dialed in for ease of detachment once the rivet is in place.

References

• Thread Rite: Pop Rivets, How do they Work?
• Natural Handyman: Put a Rivet Gun in Your Sights ... and Your Toolbox
• Emhart Teknologies: Well Nut Threaded Inserts