currently in the building market presents a huge range of screws. Is a popular fixture in industrial and civil construction, and in the conduct of household repairs in the homes and apartments.
The Standard name of the self-tapping screws according to GOST, «fasteners» — self-tapping screws. Screws similar to the screws of the Soviet era, are available in many different lengths, diameters, types of turns, color and shape of the head.
depending on the material with which we work, select the type of thread. High ridge with a rare step for connecting a soft, porous materials – plasterboard, hardboard, chipboard and MDF-Board, wood, unsteady rocks, plastic, etc. are Fragile, loose structure of plywood, for example, is well entrenched in the wider grooves of the screw, and the connection will be reliable. To work with the metal we need is a thread with a low comb and frequent step. These same screws are used when working with durable plastic and hardwood. There are also self-tapping screws with alternating threads of low and high revolutions. Double-start thread is used for bonding of parts with different density material is porous and solid. For example, drywall and sheet metal.
Screws can have a length of from 10 to 260 mm, the rod diameters vary from 1.6 to 12 mm. The diameter is directly proportional to the length of the fastener, or, in other words, the growth length increases and the diameter. Numeric marking of screws is decrypted in the following way: the first number is the outer diameter of the thread, the second one its length.Size of screw length select 4-5 millimeters longer than the total width of the fastened materials.
For the manufacture of self-tapping screws used high-quality stainless, high-carbon steel or the more expensive brass. Product color varies from black, silver and gold, coated with zinc, oxide or uncoated. Black screws with blue coating recommended for use in standard conditions of humidity. Silver galvanized coating can be used in ordinary rooms and under conditions of high humidity environment. Golden galvanized screws choose for home repairs in the colour of the joined materials.
metal Screws have a pointed end and a flat hat or everlovely the end of the head in the form of a hemisphere or design with press-washer. A hemispherical cap, in contrast to the simple flat, with the increase of the area of the contact surface ensures reliable fixing of the materials. The head with pressure washer very firmly connects the product to any density.Pin-drill forms a hole in the bond. The end passes through the metal, twisting the second material. When the thickness of metal more than two millimeters will take pre-reaming hole drill bit with a diameter of 2-3 mm less than the diameter of the screw. The remaining value of the self-tapping screw should extend itself firmly entrenched in the material. The porous wood passage for the screws drilled, but only if the length and diameter of large size.
One of the subtypes of fasteners – special screws for furniture or euroserum (confirmat). Pin length – 50 mm, blunt end. Therefore, the applied-drilling before screwing in furniture made of particleboard, MDF, etc. Diameter closer to the bonnet is slightly increased, the windings are quite high. The flat head has a groove in the shape of a hexagon under the appropriate key. After Assembly the groove is masked by the decorative cap in the color of the product.
There are more screws, called vandal-proof. A characteristic feature of non – standard grooves on the heads in the form of stars, polyhedra, under the special screwdriver.
Screws with hex head are widely spaced turns, a slightly pointed end. They are used for critical connections larger items. These fasteners can be applied to wood and concrete. In concrete, screw the screws with dowels, the diameter of which is two times more. The hole for the dowel drilled in the ratio of one-to-one, i.e. the size of the diameter of the dowel. To work with hex-screws will need keys for 10, 13 and 17 mm (longest).
one of the specialized types of screws – roofing. Have the following characteristics: the end everlovely, cap hex with rubber washer. Approach the screws on the keys 8 and 10 millimeters. Length from 19 to 100 mm. Rubber gasket is used for tight connection of the roof and prevents the ingress of moisture into the connection and, respectively, from corrosion and rust. Roofing screws come in different colors – a wide palette of tonal metal. The type of the connected materials are the screws «metal-metal» and «wood-metal». To connect the two metals take the self-tapping screw with sharp end. When attaching metal to wood rod will resemble a drill. Material rubber washers – high quality rubber EPDM (EPDM – ethylene propylene diene monomer), which has good elasticity, long time can keep their properties, without collapsing under the action of sun, rain and wind. Sheet metal, pressed rubber, less «playing». For mounting metalloproteinase sheet choose roofing screws with hemispherical cap, flat head, with rubber washer or without. Roofing fasteners can be with different coating – galvanized, polymeric color, and even layered.
On the advice of experts, 1 square meter of the roof must be fixed 8-10 of roofing screws. For more complicated designs and with the large thickness of the metal sheet to increase this number. Screw the self-tapping screws are best staggered.
In conclusion, the selection of tips from the masters on how to successfully tighten screw. By the way, it is possible to Unscrew back for reuse. Arsenal must attend a drill and screwdriver that are suitable to the selected type of screws. Otherwise, it is likely to damage the fastener. As they wear, the tools need to be updated, to prevent errors in connections. Cheap low quality screwdriver, can very quickly come into disrepair. «Cheap and cheerful» — it’s about this case. So choose a proven tool high carbon hardened steel. If a lot of work, instead of screwdriver, screwdriver required, which saves time and guarantees a strong connection. The planned place where you will install screws. Begin to tighten vigorously, at the same pace, but gently. After he felt that the screw went into the material, slightly amplified effect. And in the end – momentum and stress reduce, decrotive, trying not to ruin the fasteners.
the use of screw with dowel, the last one before screwing in the concrete wall can be covered with a layer of glue, additionally podstrahovat reliability of the connection. Pre-prepared dowel hole produced with the drill. All other tools can break, unable to withstand the load. In the plug can be tighten screw universal or for wood. If that is not screwed into the dowel, tile or brick, will use the drill. The hammer can destroy the surface, is less durable than concrete. In non-ferrous metal (bronze, for example) make a hole with a diameter of less than 1.5 – 2 mm diameter rod self-tapping universal screw without taking turns.