Steel girders – reliable and strong material which is used in construction for construction of buildings and constructions as overlappings and also for construction of suspended designs, bridges, utilities. There is set of types and brands of steel girders therefore their choice should be made taking into account these parameters.
Production of steel girders
For production of steel girders for overlappings use two methods: rolling and welding. The beams produced in the first method are called hot-rolled, and on the second – welded. Depending on method of manufacture also their cost - the price hot-rolled is determined above. But as metal beams belong to construction materials to which increased requirements of safety are imposed, their production is strictly regulated by state standard specifications therefore strength characteristics of the beams made in different ways practically do not differ - both those, and others are capable to ensure reliability and safety of any building construction.
For production of welded beams the sheet steel is cut out on strips by method of thermal cutting, and then on the assembly machine of beam weld in monolithic construction. For production of hot-rolled beams use rolling machines on which they are processed to the necessary form. In ready beams then drill openings, smooth out their surfaces and paint.
Types of steel girders
For definition of types of steel girders such characteristics as assignment, way of production, technical parameters, edges of shelves, their sizes, arrangement and width are used. There are two types of beams – cutting and continuous-solid, besides, beams happen to parallel regiments three types: wide-shelf, normal and columned.
When choosing it is necessary to consider that the beams made according to specifications of the enterprise can have marking, other than approved by state standard specifications.
Depending on length, beams are subdivided into measured, multiple measured, measured taking into account the 5% rest from the lump of party and also multiple measured taking into account the 5% rest from the lump of party and beam unmeasured. All beams having length less than 3 meters are considered to be the remains.
In separate look galvanized beams which thanks to the high anticorrosive resistance are used as high-strength frameworks at construction of multy-storey buildings are allocated.
Marking of steel girders
Each of the listed types of beams has the state standard and marking therefore to choose products necessary to you, you can, being guided by it. So, for example, the beams intended for installation in mines have marking "With", and for suspended ways – "M". High accuracy of rolling has marking "And", standard – "In". As for width of strips, letter "U" has designated beams with narrow strip, "B" - with standard, "Highway" - with wide. The special type of the beams having midland with average width is designated as "Д", columned beams have marking "To".