Self-tapping screws are a fastener with the unique feature of drilling their holes when screwed into materials such as wood, plastic, and metal. These screws are typically used when you need to attach two pieces of material where you have only access to one side of the material. The two types of self-tapping fasteners are thread-forming and thread-cutting.
Thread-forming screws
Thread-forming screws are designed for plastic which deforms the material as the screw enters. Although thread-forming screws remain in the material more tightly, there is a risk of over-tightening the screw, which could cause the material to break under pressure.
Thread-cutting screws
Thread-cutting screws, on the other hand, are typically meant for wood and metal. They remove some of the material and create an easy threaded path for the screw.
Difference between self-tapping and self-drilling fasteners:
The difference between self-tapping and self-drilling fasteners is that a self-drilling screw is essentially a self-tapping screw with the added feature of a drill point end.
Self-drilling screws eliminate the need for a pre-drilled pilot hole as they perform the drilling, tapping, and fastening in one action. While self-tapping fasteners, as the name suggests, are screws that can tap threads into the material. In short, all self-drilling screws are self-tapping, but all self-tappers are not self-drillers.
Available self-Tapping Fasteners:
The right head shape, drive type, and thread size are essential factors when choosing a fastener. In addition, the materials of the element and the type of environment to which they are exposed are also essential factors.
Enrgtech provides varieties of drive types, such as Crosshead and Pozidriv, with head shapes including Pan head and Flathead. These fasteners are steel, stainless steel with bright zinc plating and clear passivated finishes.
Most Popular types of self-tapping fasteners:
Of the various types of these screws, some of the widely used are given as under.
Countersunk/flat head screws:
These provide a flat and smooth finish as the head of the screw sits below the material's surface.
Socket head:
These are strong enough and avoid distortion due to the shape of the driver used during driving into the material.
Bugle Head Screws:
They are widely used to attach plasterboards to woods and metal studs. Due to a bugle-shaped head, they allow much more stress than a flat head screw.
Button Head Screws:
These screws are also favored due to their dome shape and avoiding countersinking into the material. They are typically used in carpentry.
Flange Head:
They are usually used to attach plastic to plastic or metal to metal.
Hex-Headed:
These screws with a hexagonal head are typically used by contractors in heavy-duty applications where a countersunk head is not required.
Wafer Head:
A flat-top surface is countersunk and the head allows a flush fit on wood and other softer materials.
Pan Head:
They are used in high torque applications in either metal or wood
Square-Headed:
These are less prone to bit-slipping than a traditional Phillips screw, and care is required to ensure that screw is not over-tightened.
Truss Head:
They have an extra wide and slightly rounded surface suitable for sheet metal and other materials with large diameter holes.
Conclusion:
Self-tapping screws are ideal for items that require regular maintenance and work well when working with different kinds of material being joined together. These fasteners come in all shapes and sizes and are available in several different head types. Finally, as a screwdriver is the only fundamental tool used, ensure that you have the screwdriver with the appropriate drive type when working with self-tappers.
