Riveting is another method of joining metals with the use of sheet metal screws. When done properly, it looks neat and serves a double purpose of joining the metal and adding decoration. The use of rivets may be determined by the kind of project and the materials used.
Rivets are madeto put parts together permanently just like screws. They are used on heavy metalwork such as those found in bridges, locomotives, boilers, and boat hulls. Heavier rivets are made of mild steel. Lighter rivets are made of copper, brass, aluminum, nickel, silver, and tinned galvanized steel. Mild steel is also used for small rivets. Rivets are sold inpackages from one to five pounds. They are also available in 50 to 100 pound kegs or small barrels.
The tools used for riveting are a solid punch, riveting hammer, and rivet set. The most commonly used hammer is the ballpeen hammer. A rivet set is a small bar of steel with a hole in one end to receive the end of the rivet and a cuplike depression used in forming the head of the rivet as it is hammered down.
Follow these steps in riveting sheet metal:
- Select the suitable rivets. If the rivet is to be part of the design, a round-head rivet is used for emphasis. Flatheads are used if the assembly is not noticeable. Rivets must be long enough to go through both pieces to be joined and extend beyond one and a half times the length of the diameter. If the back is to be flushed, the rivets must extend by only a small amount, just enough to fill the countersunk holes.
- Determine the location of the rivets. If several are to be set along a lap seam, they should be located at a distance one and a half to two times their distance from the edge. They should be equally spaced along the seam.
- Punch the holes specially if the metal is thin. Place the sheets over the end grain of a hardwood or over a lead block. Hold the solid punch in place where the hole is to be located. Strike the punch solidly with a hammer to form the hole.
- Set the rivet. Place the rivet with the head down on a flat surface or, if cylindrical objects are being riveted together, place the rivet on the crown at a stake. Slip the metal over it so that the shank comes through the hole. Place the hole in the rivet set over the shank. Then strike the rivet set once or twice with a hammer. This will flatten the sheet metal around the hole and draw the two sheets together. Do not strike the rivet set too hard. Be sure to keep it square with the workpiece, because sheet metal dents easily.
- Head the rivet. Use the flat face of the riveting hammer to strike the shank squarely with several blows. The shank will expand, filling the hole tightly while the top of the shank will flatten a little. Place the cone-shaped depression of the rivet set over the shank and strike the set two or three times to round off the head.
- When setting several rivets in a row, it is better to punch and rivet at the center hole. Then punch the other holes, riveting from the center outward.
- Check your work by answering the following questions:
- Have I dented the sheet metal around the rivet?
- Is the head well shaped?
- Do I have the rivets close to the edge?