Assortment of screw products, which are used for fasteners (hardware), is quite extensive, especially considering the types of bolts, variety of their diameter and length, mechanical properties and workmanship. they, who wants to buy high-quality hardware in bulk in Moscow can use the services of the company “Screw and Bolt”, whose site is located at the following link http://vintibolt.ru.
The class of bolts depends not only on the steel used, but also on the method of their manufacture, as well as from heat treatment. Distinguish 10 bolt classes. The screw class designation consists of two numbers separated by a dot.
Some examples
Bolts class from 3.6 to 6.8 made from carbon steel, and the class bolts 3.6, 4.6 and 5.6 produced by hot plastic processing, and the screws are class 4.8, 5.8 and 6.8 cold molding method. Bolts class 8.8, 9.8 and 10.9, usually, made from carbon steel with alloying additives and processed using plastic hardening.
Cold formation
Hex Bolts, nuts and similar connecting elements are most often produced today using the cold forming method. Press extrusion is an ideal way to produce high volume screws with small diameters and lengths. The starting material is supplied in the form of wire wound on drums - these circles can weigh up to 800 kg. In devices, before processing, the wire is cut into pieces and straightened. Stainless steel rods are suitable for this type of production.. Copper can be used in this method, brass, aluminum and aluminum alloys.
Modern cold pressing operations include subsequent operations: wire cutting, preforming the head, clearing burrs and reducing the threading part. Multi-stage presses are very efficient - they can produce up to 300 bolts in one minute.
Company “Screw and Bolt” produces hardware and connecting elements from stainless steel, which are widely used. They make bolts of any length and with different thread pitches, in all commonly used strength classes.
The company constantly conducts research into the strength of its products, on the basis of which it issues appropriate certificates and certificates of quality.
