Types of self-tapping screws, what they are

Self-tapping screws appeared on the market not so long ago, but they very quickly replaced their “big brother” - the screw. It is believed that these two fasteners are practically no different from each other. However, a self-tapping screw (the second name for a self-tapping screw) is more convenient to use and there are several varieties of it, which helps make it easier to work on different surfaces.

What types of screws are there?

Self-tapping screws are classified according to several criteria:

• material of manufacture;
• design;
• appointment.

Let's take a closer look.

Material of manufacture

The technique for producing self-tapping screws is much more complicated than a regular screw. So, this type of fastener is made exclusively from high-quality alloys, and then subjected to heat treatment. The self-tapping screw can be made from:

• high carbon steel;
• stainless steel;
• brass

You should also know that self-tapping screws may differ in coating material:

• phosphated (black);
• oxidized (black);
• galvanized;
• galvanized yellow;
• without cover.

Design

The self-tapping screw consists of several parts:

1. The head is the top part of the part. It can be countersunk, hexagonal, semicircular, with a press washer, cone-shaped, cylindrical.
2. A slot is a special recess in the head for transmitting torque from the tool to this product. There are straight, cruciform, hexagonal, and six-rayed star shaped.There are also combined self-tapping screws, where a cross-shaped slot and a straight slot are simultaneously present.
3. The thread is double-threaded, rare, frequent.
4. The end is sharp or drilled.

Purpose

The scope of the self-tapping screw largely depends on its design. So, the fastener can be:

• Universal. Used when working with various materials, such as metal, wood, brick, concrete, hollow or solid structures. Hardware got its name by ensuring efficient installation and creating reliable connections on any surface.
• On wood. As the name implies, this type of self-tapping screw is used for wood work. It does not have cutting edges at the end, its thread is much more pronounced and the pitch is larger.
• For plasterboard and gypsum fiber sheets. Self-tapping screws for drywall have different sizes and mounting options. When choosing such fasteners, it is important where exactly the sheet will be attached. So, for metal structures this is one type of self-tapping screws for drywall, for wood - another.
• For sheet metal and metal profiles. This type of fasteners is used to fasten one metal surface to another, as well as metal profiles to wood, plastic or any other surface. Available with a pointed end or with a drill. Characterized by a frequent thread pitch with small spaces between turns.
• For window profile. They are mainly used in factories that produce window profiles. They are used for screwing into plastic to fasten profiles to other elements.
• Roofing. These self-tapping screws come in two types: metal and wood. They differ only in two characteristics. Firstly, this is the tip.For wood it is sharp, for metal it is two-bladed in the form of a drill (borer). Secondly, this is the type of thread. On wood it is larger in terms of the height of the thread profile and the pitch of the location. They are equipped with a washer with a rubber gasket, which is responsible for the tightness of the connection, which is important for roofing to prevent leaks.