Riveting is a way of joining metals or some other materials. Rivets are made from malleable metals such as iron, steel, copper, brass, aluminum or aluminum alloys.
There are three main types of rivet:
Snags or roundheads are used for general metalwork where countersinking would weaken the plates and where a flush finish is not required.
Flat heads are used for thin plate work, often for repairing gardening equipment such as grass boxes and metal wheelbarrows.
Countersunk 90 degree rivets are the most common form of countersunk rivet, and they are used when a flush finish is required – provided the metals used are thick enough to accommodate the countersink.
When choosing a rivet, its diameter should be not less than the thickness of one of the plates to be riveted, and not more than three times its thickness. To form a round head, the shank of the rivet must project 1 1/4 times the diameter of the shank, and for a countersunk head an amount equal to the diameter. In every case, the rivet must fit exactly the hole in which it is to be used.
When calculating the number of rivets required, spacing between rivets should be three times the diameter of the rivet across the width of the metal and twice the diameter down the length.
Rivets should be set 1 Ã?Â½ times their diameter from the edge of the metal they are to hold.
Tools needed for riveting are:
Set and Snap
A rivet set is a piece of metal which has a hole the same diameter as the rivet shank. It is placed over the shank of a rivet after it has been pushed through the materials it is to fix. The set is then struck with a hammer to drive the plates tightly together.
The river snap, or dolly, is a solid piece of metal with a concave hole in one end, the same shape as a rivet head. It is used to form a neat, rounded head to the rivet after it has been roughly shaped.
The set and snap are available separately, or they may be combined. If combined you will need an additional snap or a piece of hardwood to support the river head while the shank of the river is being formed.
This has a rounded head, opposite the flat face, which is used ti rough shape a rivet.
Firmly clamp the two pieces of metal together in a vice. Mark the position of the holes, then use a high speed twist drill the same diameter as the rivet and drill through both sheets.
Check there is no swarf. If there is, use a file to remove it, then pass the rivet through the holes. Take the metal out of the vice and hold the rivet head on a piece of hardwood. Place the set over the shank and strike it with a hammer to bring the two sheets in close contact. Use the flat face of the hammer to swell the shank of the rivet, then use the ball-pein end to rough shape the rivet.
If countersunk rivets are to be used, use a countersunk bit to form the countersinks in the metal sheets. Check with a rivet to ensure the countersinks are deep enough to take the head. Support countersunk heads on a flat metal block while the rivet is formed. Then use a file to smooth the rivet flush with the sheets.
As an alternative to hand riveting you can use a small tool resembling a pair of pliers. It has the advantage of fixing rivers from one side of the work only. The only disadvantage is that, being hollow, the rivets are not as strong as solid rivets of the same diameter. They are best suited to thin metals, such as car bodywork.
The hollow rivet contains a pin, called a mandrel, which is inserted into the riveting tool.
Drill through both materials to be riveted, then select a pop rivet of suitable length and insert it in the riveting tool. Press the rivet through the hole; hold firmly in place and squeeze the trigger of the tool. This draws the mandrel towards the tool, expanding the rivet on the far side of the hole. Keep squeezing, and the mandrel will break away from the head, and can be withdrawn from the tool.
Riveting kits, containing the tool and a selection of pop rivets, are available from tool stores and car accessory shops.