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

日本中文字幕A级 | 亚洲无码在线一区二区三区 | 成人精品1999 | 人妻人人干人人操精品大全 | 四川少妇BBw搡BBBB槡BBBB 国产全肉乱妇杂乱视频 | 无码人妻一区二区三区三 | 日韩人妻无码中文一区二区三区 | 青青青青青依人精品视频 | 99无码在线观看成人一起草 | 少妇又爽又紧刺激视频在线播放 | 国产美乳视频一区二区免费 | 激情图片无毒不卡欧美色图 | 黑人在线播放一区二区三区 | 少妇搡BBBB搡BBB搡小说 | 原千岁超级溺爱儿观看 | 成人免费网站www污污污在线看 | 99热这里只有精品666 | 久久国产亚洲无码 | 亚洲一区AV二区三区在线观看 | 亚洲妇女蜜桃AV网站 | 人与禽一级婬片A片老牛 | 91精品国产aⅴ一区二区 | 亚洲国产成人精品久久久9 精品国产无码一区二区三区 | 高潮抽搐在线观看 | 国产打电话系列A片在线观看 | 激情小说激情图片 | 免播放器激情肏屄视频 | 午夜国产小视频在线看 | 国产欧美日韩视频 | 一级伦奷片高潮无码看了5 91精品乱码久久蜜桃麻豆 | 又大又粗又硬又黄的少妇视频 | 爱爱小视频男人的天堂 | 成人精品天堂一区二区三区 | 夜夜躁狠狠躁日日躁av | 欧美一级BBBB高潮片 | 另类TS人妖一区二区三区 | 精品无人区少妇太爽高潮在线播放 | 被强行糟蹋的女人A片 | 亚洲欧美一区二区狠狠插 | 黑人糟蹋人妻hd中文字幕 | 亚洲一区二区三区无码国产宅男噜 |