Peculiarities
It's no secret that all the self-tapping screws that exist today are primarily distinguished by their purpose. That is, each type is intended for attaching a specific material. But there is a product among the assortment that can be used for fastening different materials. A universal self-tapping screw is a fastener, using which you can connect metal, wood, plastic, drywall and other types of materials. A universal screw consists of the following elements:
- head;
- kernel;
- tip.
These fasteners are manufactured in accordance with the rules and requirements that are provided for in regulatory documents: GOST. They also control and regulate all parameters and physical and technical properties of the product. Detailed information on what the fasteners should be is specified in GOST 1144-80, GOST 1145-80, GOST 1146-80. According to GOST, the product must be:
- durable;
- reliable;
- provide a good bond;
- corrosion resistant;
- resistant to mechanical stress.
Among the existing features of the universal self-tapping screw, it is also worth noting the installation method. There are 2 ways.
- The first involves preparatory work. If the insert of the product is made into a hard material, for example, metal, as well as into hard wood, you must first make a hole using a special tool, into which a self-tapping screw is then screwed.
- The second method involves screwing in a self-tapping screw without pre-drilling. This option is possible if the product is screwed into soft plastic or wood.
What are they?
There are many types and classifications of the fastener. According to GOST, universal screws differ in different parameters.
- The nature and height of the thread. The latter is single-threaded or double-threaded, its height may be the same or with turns.
- The size of the thread pitch. It can be large, small or special.
- Head shape. Distinguish between square, hexagonal, semicircular, semi-secret and secret. The most popular is countersunk head fasteners. Such a product guarantees the creation of a strong knot between the parts and a flat surface after screwing in, since the head is completely hidden in a special opening.
- Slot shape.
According to this criterion, several types of connecting products are distinguished.
- Galvanized or SHUTS (decoding: "universal zinc screw"). For the coating, zinc is used, which contributes to an increase in corrosion resistance. Self-tapping screws are characterized by strength, reliability and long service life.
- Chrome plated. This type of fastener is most often used to connect parts that will be used in severe weather conditions.
- Made of stainless steel. These are expensive self-tapping screws, since their physical and technical parameters are quite high.
- From ferrous metals. Ferrous metal self-tapping screws are rarely used. It is not highly corrosion resistant and durable.
- From non-ferrous metals. These are brass self-tapping screws, which are most often used in the process of assembling furniture.
