U-shaped steel (full name: mine roadway support hot-rolled U-shaped steel)
U-section steel is a type of steel with a cross-section like the letter "U," sometimes with a cross-section in the shape of the Japanese letter "ひ."
The latest standard was released in 2008, on April 1, 2009 implementation of the national recommended standards
GB / T 4697-2008
U-shaped steel bracket
Main features: under pressure, support a long time, easy to install and easy deformation characteristics.
Main purposes: Mainly used for mine roadway, mine roadway secondary support, as well as supporting the use of tunnel support and other purposes.
As the main section steel for making tunnel scalable metal stents, U-section steels are widely used both at home and abroad.
However, due to the inconsistent understanding of the properties and requirements of the U-shaped steel, the cross-sectional shapes, geometrical parameters and materials of U-shaped steel in various countries are not the same.
China's U-shaped steel production models are mainly 18U, 25U, 29U, 36U four. One of the first two of the Department of 60's products, is a waist positioning; the latter two are 80's products, is the ear location. U18 is rarely produced due to its low carrying capacity.
In GB / T 4697-2008 in addition to the above four models of U-shaped steel, the new 40U this model.
The weight of each type of U-beam is as follows:
18UY 18.96 kg / m
25UY 24.76 kg / m
25U 24.95 kg / m
29U 29 kg / m
36U 35.87 kg / m
40U 40.05 kg / m
After the model with "Y" said for the waist positioning.
U-type steel varieties: cold-formed U-shaped steel, large U-shaped steel, U-shaped steel for automobiles, hot dip galvanized U-shaped steel and other open cold-formed steel.