Most of people well knows that before purchase of outer door first of all it is necessary to decide on all requirements to which future acquisition has to answer. Only then it is possible to choose sample which will correspond most fully to both the financial opportunities, and personal tastes.
Today all outer doors classify by one parameter — the used material for their production. They happen: 1) steel;
2) metal; 3) aluminum; 4) wooden; 5) plastic. Further the speech about steel door assemblies which are in huge demand for the population now will go. The qualitative steel shutter has to provide the most reliable protection of the room, that is it is good to resist to breakings, various physical impacts, the fires and in certain cases even to firearms. Degree of reliability of such design is determined by several criteria at once, is basic of which resistance to breakings. According to the existing standards, doors from steel on degree of vzlomostoykost are provided by 13 classes. Designs of the first four classes are used in various premises, and all others — in numerous public and public institutions, warehouse, etc. It is important to realize that in the world there are no doors which cannot be opened, even despite long beliefs of sellers about opposite. It is possible to open any door — only certain time and the necessary tool is required. Only duration of this "procedure" matters. Naturally, the longer the malefactor will potter with door, the better it for the owner of the room.
All steel shutters differ among themselves only with time span necessary for their opening. For example, the design of the first class of vzlomoustoychivost opens by means of nail-catcher, mount or metal scrap within 5-9 minutes, and the system of the 4th class will require already much more time — 23-35 minutes. But there is possibility of increase in reliability of steel shutters assuming use of special systems from so-called active and passive crossbars. They allow to exclude completely any breaking by mechanical means. One more parameter defining degree of reliability of doors from steel is availability of special devices of opening and locking. They represent various revolving objects, keys, including electronic, magnetic cards and many other devices for identification. Also various remote systems are widely used. The qualitative steel shutter has to possess at least two castle mechanisms. To increase safety of such designs, it is recommended to cut locks of two versions — suvaldny, acting as the main mechanism, and cylinder as additional element. Such combination is the most suitable as the level lock perfectly resists to power influences, and it is very difficult to open the cylinder mechanism with application of master key. The steel shutter should be equipped with the high-quality burglar retardant protection interfering possible removal of design from loops. Due attention upon purchase of steel shutter should be paid to external finishing. Ways of execution of both internal, and external finishing exists much, beginning from the most modest and unpretentious and finishing magnificent and elegant. The choice of door in this parameter depends on type of the building for which it intends. In addition It is necessary to tell that the steel entrance structure can be decorated in every possible way, but not to forget that its registration has to be combined with surrounding design harmoniously.