5. Fasteners

The term 'Fasteners' refers to hardware that is used to fasten something to another thing by a mechanical method. In this curriculum, we only cover basic fasteners used in metal technology.

Solid Rivets

Solid rivets are made from a soft steel alloy, and their whole function is to hold two parts together mechanically. They are used in combination with a punch and hammer.

The idea is to hammer the solid rivet and upset, or mushroom, the end over on each side of the rivet. This locks the two materials together with a mechanical method. Rivets are used in civil engineering for steel structures, heavy industry transportation, and the aeronautical industry.

Solid rivets can be used cold or hot. Because of the way it is used, it is important to secure the punches and anvils used securely, as you will need both hands to hold the material and use the hammer.

PPE for this procedure would be safety glasses, as debris can fly off the end of the rivet when you are mushrooming the end over.

Pop Rivets

Pop rivets are very similar to solid rivets. They also use a mechanical method to hold two items together. However, they tend to be less robust, so they are not used on structural frames or members.

To use a pop rivet you will need a pop rivet gun. The way they work is that the central shaft on the pop rivet is pulled inwards by squeezing the gun handles together. This mushrooms the end of the rivet open, and in this way it clamps two individual items together.

It is important to secure the material you are working on when riveting. Be aware that the central part of the pop rivet can fly out the gun when it snaps off, so safety glasses are a must-have.

Screws

Screws are used in engineering all the time, but to differentiate them from screws that are used in carpentry or joinery, we refer to them as tec screws. The term self-tapping screws or self-drilling screws can also be used. They are specifically designed to work on sheet metal.

As with any fastener, secure your material before you use it. A pilot hole is a must-have to use tec screws. Always drill the pilot hole slightly smaller than the size of the screw.

Nut & Bolts

Nuts and Bolts are widely used in the industry. From Civil, Mechanical and Carpentry. The style and design differs slightly, and there are a few varieties of Nut design and Bolt design. All nuts and bolts, regardless of design, use a clamping force to mechanically lock two parts together.

The heads of the bolts and be designed for a spanner, a screw driver or a socket. Nuts can be designed for spanners or for sockets. Bolts and nuts can also come in different thread pitch sizes and diameters.

It is important not to over tighten a bolt and nut as the thread can be stripped or broken off completely, making the bolt and nut incapable ot function as intended.

Here are some examples of diffrent threads and different fastener head designs.

The right image shows, from the top down : Flat, Phillips, Supadriv, Pozidriv, Combination Flat/Phillips, Allen/Hex, Robertson/Square.

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