亚洲最黄视频-亚洲最大在线-亚洲最大网址-亚洲最大色网-亚洲最大色视频-亚洲最大情网站在线观看

U-shaped steel

U-shaped steel

DESCRIPTION

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


DETAILS

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.

RELATED PRODUCTS

裸体美女国产免费久久久网站 | 中文字幕无码视频 | 亚洲无碼熟女寂寞少妇 | 国产午夜福利在线观看视 | 无码人妻一区二区三区线花季传媒 | 男女后进式猛烈XX00动态图视频 | 精品蜜桃少妇高潮呻吟久久久 | 中文字幕理伦成熟少妇 | 无码人妻一区二区三区线花季传媒 | 精品人妻一区二区三区久久久久 | 成人网站视频无码免费 | 四川少妇搡BBB搡BBB搡多人伦 | 91精品久久久久久久久久久久 | 专干老妇熟女6070频 | 在线观看免费黄片 | 9999热视频在线看 | 99精品在线播放 | 日韩欧美成人在线免费观看 | 久久丫精品久久丫 | 91精品人妻一区二区三区不卡 | 国产一级毛片视频 | 99精品国产在热久久婷婷 | 佐山爱一区二区在线观看免费 | 91在线免费视频播放 | 亚洲视频在线观看视频在线观看视频 | 人妻国产精品一区二区 | 欧韩乱伦一区二区三区 | 国产成人精品二三区麻豆 | 黄色av免费观看免费网站 | 亚洲第一视频网站 | 91久久精品人人做人人爽综合 | 男人下面一起进入网站 | 国产激情婬妇A片视频车文 日本熟女性爱一区二区三区 | 久久久久亚洲国产精品88av | 2025国产精品主播在线 | 国产一区二区三区探花精品 | 自拍偷拍,国内视频亚洲视频 | 国产无套内精一级毛片三 | 亚洲AⅤ秘无码一区二区三区 | 白丝刚交自慰在线观看 | 人妻少妇无码精品 |