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

熟妇人妻无乱码中文字幕蜜桃 | 处破初破苞一区二区三区在线播放 | 大又大又粗又硬又爽少妇毛片 | 日日夜夜爽爽狠狠 | A级毛片成人动漫aaaa | 精品在线观看小视频 | 扒开极品粉嫩小仙女 | 97人妻人人做人碰人人爽一二 | 国产伦精品一区二区三区视频软件 | 国产精品内射在线观看 | 卡通动漫亚洲日韩国产专区 | 午夜精品人妻无码 | 中文字幕在线观看一区二区 | 免费在线观看内射 | 日本午夜福利视频 | 97av在线视频免费观看 | 国产真人真事一级A片 | A片无限看站长推荐 | 又黄又粗又硬又嫩视频 | 小向美奈子高清加勒比 | 少妇熟女a v精品一区二区 | 91在线无码精品秘 蜜桃 | 肥婆老BBB肥婆BBBBB | 日韩精品一区二区三区免费视频 | 日本不卡中文字幕 | 人妻交换 日韩欧美 久久91 | 人人妻人人澡人人爽欧美一区久久 | 6080yyy午夜理论 | 成人H动漫精品一区二区无码 | 国产一区二区三区手机在线观看 | 日韩色图一区二区三区 | 成人乱妇无码AV在线 | 久久国产精品一区二区 | 欧美人妻少妇一区二区 | 亚洲AV无码国产精品综合 | 国产又大又粗又猛又硬 | 成人网站在线观看网址 | 久久午夜夜伦鲁鲁片无码免费 | 韩国一级婬片A片AAA小说软件 | 最近最新字幕MV在线观看预告 | 免费观看自慰喷水www久久久 |