工字钢也称为钢梁（英文名称 I Beam)，是截面为工字形状的长条钢材。工字钢分普通工字钢和轻型工字钢，H型钢三种。工字钢广泛用于各种建筑结构、桥梁、车辆、支架、机械等。

I-steel beam (also known as English name I Beam), is an H-shaped steel strip section. I-steel is divided into three kinds: ordinary I-steel and light I-steel, H type steel. I-steel is widely used in various architectural structures, bridges, vehicles, stents, machinery and so on.

型材是铁或钢以及具有一定强度和韧性的材料通过轧制、挤出、铸造等工艺制成的具有一定几何形状的物体。这类材料具有的外观尺寸一定，断面呈一定形状，具有一定的力学物理性能。BecausetheshapeofthesectionisthesameasthatoftheEnglishletter"H"。型材既能单独使用也能进一步加工成其他制造品，常用于建筑结构与制造安装。型材的材质、规格尺寸等可参照相应的***标准。轧机结构和轧机布置形式较多。在结构形式上有二辊式轧机、三辊式轧机、孔型轧机、多辊孔型轧机、Y型轧机、45°轧机和悬臂式轧机等。

有的胶合板是将两个不同纹路的单板贴在一起制成的，所以在选择上要注意夹板拼缝处应严密，没有高低不平现象。挑选胶合板时，应注意挑选不散胶的胶合板。如果手敲胶合板各部位时，声音发脆，则证明质量良好，若声音发闷，则表示胶合板已出现散胶现象。

Some plywood plywood is made of two different lines of the single board together, so in the choice of the splints should be careful to pay attention to the joint, there is no uneven phenomenon. When choosing plywood, you should pay attention to selecting plywood without glue. If the hand knocks on the plywood parts, the sound is crisp, which proves that the quality is good. If the voice is stuffy, it means that the plywood has already appeared loose glue phenomenon.